Code quality

* Create a makefile (for *nix only, right?)
* Configure code coverage and tests
* Configure linter
* Configure linter for errors only

Makefile

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+.PHONY: coverage errors
+
+coverage:
+	cd src/; coverage run --source='.' manage.py test; coverage report -m; cd ..
+	@echo "Testing of coverage in the sources finished."
+
+lint:
+	pylint src/* --disable=django-not-configured
+
+errors:
+	pylint src/* --errors-only --disable=django-not-configured

requirements/dev.txt

@@ -6,4 +6,5 @@ flake8==3.9.1
 django-spaghetti-and-meatballs==0.4.2
 docutils==0.16
 pytest==6.2.4
-pytest-django==4.2.0
+pytest-django==4.2.0
+

src/.coveragerc

@@ -0,0 +1,15 @@
+[run]
+branch = true
+omit =
+        */tests/*
+        */test*
+        */migrations/*
+        */urls.py
+        */settings/*
+        */wsgi.py
+        */__init__.py
+        manage.py
+source = .
+
+[report]
+show_missing = true