Added coverage to testing

.gitignore

@@ -3,3 +3,4 @@ __pycache__/
 backup_tool
 *.egg-info/
 .tox/
+.coverage

setup.py

@@ -11,6 +11,10 @@ setup(
         "ci": [
             "tox==3.21.1",
         ],
+        "test": {
+            "pytest==6.2.3",
+            "pytest-cov==2.11.1",
+        },
         "lint": [
             "black==20.8b1",
             "flake8==3.8.4",

tox.ini

@@ -2,13 +2,14 @@
 envlist = py36,py37,py38,py39,lint
 
 [testenv]
-deps = pytest
+deps = .[test]
 commands =
     pytest
+    pytest --cov=app --cov-fail-under=90 tests/
 
 [testenv:lint]
 basepython = python3.6
 deps = .[lint]
-       
-commands = black --check setup.py app
-           flake8 setup.py app
+commands =
+    black --check setup.py app
+    flake8 setup.py app