feat: added files to encourage PEP8

Makefile

@@ -0,0 +1,41 @@
+# Makefile with some simple commands to make developer's life easier
+
+
+install-requirements: install-build-essential
+	pip install -r requirements.txt
+
+dev/install-requirements: install-requirements
+	pip install -r requirements.dev.txt
+
+install-build-essential:
+	sudo apt-get update
+	sudo apt-get install build-essential
+
+update-setuptools:
+	pip install --upgrade setuptools wheel
+
+test-unit:
+	pytest tests
+	@echo 'unit tests OK'
+
+lint:
+	pylint cobra
+	@echo 'lint OK'
+
+lint-minimal:
+	pylint E cobra
+	@echo 'lint minimal OK'
+
+typecheck:
+	mypy cobra
+	@echo 'typecheck OK'
+
+codestyle:
+	pycodestyle cobra
+	@echo 'codestyle OK'
+
+docstyle:
+	pydocstyle cobra
+	@echo 'docstyle OK'
+
+code-qa: typecheck codestyle docstyle lint-minimal

requirements.dev.txt

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+mypy>=0.942
+pycodestyle>=2.8.0
+pydocstyle>=6.1.1
+pylint>=2.13.7
+pytest>=7.1.1
+pytest-mock>=3.7.0