diff --git a/Makefile b/Makefile
index ab0f16e..e6e77ec 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ venv: $(VENV)/bin/activate
 
 # Format the codebase using Black
 format: venv
-	@ '$(VENV)/bin/black' setup.py app
+	@ '$(VENV)/bin/black' setup.py app/*.py app/**/*.py
 .PHONY: format
 
 # Remove any temporary files
diff --git a/app/exceptions.py b/app/exceptions.py
deleted file mode 100644
index 1ebfe95..0000000
--- a/app/exceptions.py
+++ /dev/null
@@ -1,36 +0,0 @@
-"""Common exceptions raised by the program."""
-from typing import Union, List
-
-
-class InvalidKeyError(Exception):
-    """Thrown when a config file contains an invalid key."""
-
-    def __init__(self, keys: Union[str, List[str]]):
-        """Create a new InvalidKeyError object with the given key.
-
-        Args:
-            keys: the invalid key(s)
-        """
-        if type(keys) == str:
-            keys = [keys]
-
-        self.message = "Invalid key(s): {}".format(", ".join(keys))
-
-        super().__init__()
-
-
-class MissingKeyError(Exception):
-    """Thrown when a required key is missing from a config."""
-
-    def __init__(self, keys: Union[str, List[str]]):
-        """Create a new MissingKeyError object with the given key.
-
-        Args:
-            keys: the invalid key(s)
-        """
-        if type(keys) == str:
-            keys = [keys]
-
-        self.message = "Missing key(s): {}".format(", ".join(keys))
-
-        super().__init__()
diff --git a/app/skeleton.py b/app/skeleton.py
index c12bd45..b6e871a 100644
--- a/app/skeleton.py
+++ b/app/skeleton.py
@@ -1,6 +1,33 @@
 """Handles merging with the skeleton config."""
 from typing import Dict
-from .exceptions import InvalidKeyError, MissingKeyError
+
+
+class InvalidKeyError(Exception):
+    """Thrown when a config file contains an invalid key."""
+
+    def __init__(self, key: str):
+        """Create a new InvalidKeyError object with the given key.
+
+        Args:
+            key: the invalid key
+        """
+        self.message = "Invalid key: {}".format(key)
+
+        super().__init__(key)
+
+
+class MissingKeyError(Exception):
+    """Thrown when a required key is missing from a config."""
+
+    def __init__(self, key: str):
+        """Create a new MissingKeyError object with the given key.
+
+        Args:
+            key: the invalid key
+        """
+        self.message = "Missing key: {}".format(key)
+
+        super().__init__(key)
 
 
 def merge(*dicts: [Dict]) -> Dict:
@@ -66,10 +93,10 @@ def merge_with_skeleton(data: Dict, skel: Dict) -> Dict:
         * Split info less complex functions
     """
     # First, check for illegal keys
-    invalid_keys = list(filter(lambda k: k not in skel, data))
+    key = next(key not in skel for key in data)
 
-    if invalid_keys:
-        raise InvalidKeyError(invalid_keys)
+    if key:
+        raise InvalidKeyError(key)
 
     # Then, check the default values
     for key, value in skel.items():
diff --git a/renovate.json b/renovate.json
index 9775346..dca187a 100644
--- a/renovate.json
+++ b/renovate.json
@@ -1,3 +1,10 @@
 {
-    "$schema": "https://docs.renovatebot.com/renovate-schema.json"
+    "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+    "packageRules": [
+        {
+            "matchUpdateTypes": ["minor", "patch", "pin", "digest"],
+            "automerge": true,
+            "automergeType": "branch"
+        }
+    ]
 }
diff --git a/tests/test_dict_merge.py b/tests/test_dict_merge.py
deleted file mode 100644
index 2da81bf..0000000
--- a/tests/test_dict_merge.py
+++ /dev/null
@@ -1,69 +0,0 @@
-"""Tests for the skeleton module."""
-from app.skeleton import merge
-
-
-def test_merge_empty():
-    """Test correct response for an empty merge."""
-    assert merge() == {}
-
-
-def test_merge_single():
-    """Test merge command with a single input."""
-    assert merge({}) == {}
-
-    dic = {"test": "value", "test2": "value2"}
-
-    assert merge(dic) == dic
-
-
-def test_merge_double_no_overlap():
-    """Test merge command with two non-overlapping inputs."""
-    d1 = {"test": "value", "test2": "value2"}
-    d2 = {"test3": "value3"}
-    d_res = {"test": "value", "test2": "value2", "test3": "value3"}
-
-    assert merge(d1, d2) == d_res
-
-
-def test_merge_double_overlap():
-    """Test merge command with two overlapping inputs."""
-    d1 = {"test": "value", "test2": "value2"}
-    d2 = {"test2": "value3"}
-    d_res = {"test": "value", "test2": "value3"}
-
-    assert merge(d1, d2) == d_res
-
-
-def test_merge_triple_no_overlap():
-    """Test merge command with three non-overlapping inputs.
-
-    This test tells us that the recursion works.
-    """
-    d1 = {"test": "value", "test2": "value2"}
-    d2 = {"test3": "value3"}
-    d3 = {"test4": "value4"}
-    d_res = {
-        "test": "value",
-        "test2": "value2",
-        "test3": "value3",
-        "test4": "value4",
-    }
-
-    assert merge(d1, d2, d3) == d_res
-
-
-def test_merge_triple_overlap():
-    """Test merge command with three overlapping inputs.
-
-    This test tells us that the recursion works.
-    """
-    d1 = {"test": "value", "test2": "value2"}
-    d2 = {"test3": "value3"}
-    d3 = {"test2": "value4"}
-    d_res = {
-        "test": "value",
-        "test2": "value4",
-        "test3": "value3",
-    }
-
-    assert merge(d1, d2, d3) == d_res
diff --git a/tests/test_skeleton.py b/tests/test_skeleton.py
index 6cebba6..2da81bf 100644
--- a/tests/test_skeleton.py
+++ b/tests/test_skeleton.py
@@ -1,70 +1,69 @@
-"""Tests wether the skeleton merge works."""
-from app.skeleton import merge_with_skeleton, MissingKeyError, InvalidKeyError
-from app.exceptions import InvalidKeyError, MissingKeyError
-import pytest
+"""Tests for the skeleton module."""
+from app.skeleton import merge
 
 
-def test_single_invalid_key():
-    """Tests wether an InvalidKeyError is correctly thrown for a single key."""
-    data = {
-        "test": 1,
-        "test2": "test"
-    }
-    skel = {
-        "test": None,
+def test_merge_empty():
+    """Test correct response for an empty merge."""
+    assert merge() == {}
+
+
+def test_merge_single():
+    """Test merge command with a single input."""
+    assert merge({}) == {}
+
+    dic = {"test": "value", "test2": "value2"}
+
+    assert merge(dic) == dic
+
+
+def test_merge_double_no_overlap():
+    """Test merge command with two non-overlapping inputs."""
+    d1 = {"test": "value", "test2": "value2"}
+    d2 = {"test3": "value3"}
+    d_res = {"test": "value", "test2": "value2", "test3": "value3"}
+
+    assert merge(d1, d2) == d_res
+
+
+def test_merge_double_overlap():
+    """Test merge command with two overlapping inputs."""
+    d1 = {"test": "value", "test2": "value2"}
+    d2 = {"test2": "value3"}
+    d_res = {"test": "value", "test2": "value3"}
+
+    assert merge(d1, d2) == d_res
+
+
+def test_merge_triple_no_overlap():
+    """Test merge command with three non-overlapping inputs.
+
+    This test tells us that the recursion works.
+    """
+    d1 = {"test": "value", "test2": "value2"}
+    d2 = {"test3": "value3"}
+    d3 = {"test4": "value4"}
+    d_res = {
+        "test": "value",
+        "test2": "value2",
+        "test3": "value3",
+        "test4": "value4",
     }
 
-    with pytest.raises(InvalidKeyError) as e_info:
-        merge_with_skeleton(data, skel)
-
-    assert e_info.value.message == "Invalid key(s): test2"
+    assert merge(d1, d2, d3) == d_res
 
 
-def test_multiple_invalid_keys():
-    """Tests wether an InvalidKeyError is thrown for multiple keys."""
-    data = {
-        "test": 1,
-        "test2": "test",
-        "test3": "test",
-    }
-    skel = {
-        "test": None,
+def test_merge_triple_overlap():
+    """Test merge command with three overlapping inputs.
+
+    This test tells us that the recursion works.
+    """
+    d1 = {"test": "value", "test2": "value2"}
+    d2 = {"test3": "value3"}
+    d3 = {"test2": "value4"}
+    d_res = {
+        "test": "value",
+        "test2": "value4",
+        "test3": "value3",
     }
 
-    with pytest.raises(InvalidKeyError) as e_info:
-        merge_with_skeleton(data, skel)
-
-    assert e_info.value.message == "Invalid key(s): test2, test3"
-
-
-def test_single_missing_key():
-    """Tests wether a MissingKeyError is correctly thrown for a single key."""
-    data = {
-        "test": 1,
-    }
-    skel = {
-        "test": None,
-        "test2": None,
-    }
-
-    with pytest.raises(MissingKeyError) as e_info:
-        merge_with_skeleton(data, skel)
-
-    assert e_info.value.message == "Missing key(s): test2"
-
-
-def test_multiple_missing_keys():
-    """Tests wether a MissingKeyError is correctly thrown for multiple keys."""
-    data = {
-        "test": 1,
-    }
-    skel = {
-        "test": None,
-        "test2": None,
-        "test3": None,
-    }
-
-    with pytest.raises(MissingKeyError) as e_info:
-        merge_with_skeleton(data, skel)
-
-    assert e_info.value.message == "Missing key(s): test2, test3"
+    assert merge(d1, d2, d3) == d_res