Overhaul repository with newest bestest practices

Add typing stub file
Add metadata tests
Add missing dev dependencies
Add merge conflict check pre-commit
Add tox env for py3.9
Update license from MIT to GPL3
Update pyproject with pypi metadata
Update makefile to reduce duplication and add missing targets
Update dependencies to latest versions
Update pre-commit config to piggy back on poetry env
Update pyproject to use poetry-core
Update toxfile to use locked dependencies
Remove unused codeowners file
Remove placeholder test

tox.ini

@@ -1,48 +1,78 @@
 [tox]
-envlist = py37, py36, lint, typing, security, docs
+envlist = py36, py37, py38, py39, static, static-tests, security, docs
 isolated_build = true
+skip_missing_interpreters = true
 
 [testenv]
-description = Run the unit tests (pytest)
-deps =
+description = Run the tests
+require_locked_deps = true
+locked_deps =
     pytest
     pytest-cov
+    toml
 commands =
-    pytest --cov={envsitepackagesdir}/keyosk --cov-config .coveragerc tests/ --cov-report term-missing
+    pytest --cov={envsitepackagesdir}/keyosk --cov-config {toxinidir}/.coveragerc --cov-report term-missing {toxinidir}/tests/
 
-[testenv:lint]
-description = Check code formatting against black and pylint
-deps =
+[testenv:static]
+description = Static formatting and quality enforcement
+basepython = python3.8
+platform = linux
+ignore_errors = true
+require_locked_deps = true
+locked_deps =
     pre-commit
-    pylint == 2.3.1
-    astroid == 2.2.5
-commands =
-    pre-commit run --all-files
-    pylint keyosk
-
-[testenv:typing]
-description = Check type annotations with mypy
-deps =
+    black
+    blacken-docs
+    reorder-python-imports
+    pylint
     mypy
 commands =
-    mypy keyosk --ignore-missing-imports --no-strict-optional
+    pre-commit run --all-files
+    pylint --rcfile {toxinidir}/.pylintrc {toxinidir}/keyosk/
+    mypy --ignore-missing-imports --no-strict-optional {toxinidir}/keyosk/
+
+[testenv:static-tests]
+description = Static formatting and quality enforcement for the tests
+basepython = python3.8
+platform = linux
+ignore_errors = true
+require_locked_deps = true
+locked_deps =
+    pylint
+    mypy
+commands =
+    pylint --rcfile {toxinidir}/.pylintrc {toxinidir}/tests/
+    mypy --ignore-missing-imports --no-strict-optional {toxinidir}/tests/
 
 [testenv:security]
-description = Check security vulnerabilities (bandit)
-deps =
+description = Security checks
+basepython = python3.8
+platform = linux
+ingore_errors = true
+require_locked_deps = true
+skip_install = true
+locked_deps =
     bandit
+    safety
+allowlist_externals =
+    poetry
 commands =
-    bandit --recursive keyosk
+    bandit --recursive --quiet {toxinidir}/keyosk/
+    bandit --recursive --quiet --skip B101 {toxinidir}/tests/
+    poetry export --format requirements.txt --output {envtmpdir}/requirements.txt --without-hashes --dev
+    safety check --bare --file {envtmpdir}/requirements.txt
 
 [testenv:docs]
-description = Build documentation to check RST syntax (sphinx)
-deps =
-    sphinx >= 1.7.5, < 2.0
-    sphinx-autodoc-typehints >= 1.3.0, < 2.0
-whitelist_externals =
+description = Build sphinx documentation
+basepython = python3.8
+platform = linux
+require_locked_deps = true
+locked_deps =
+    sphinx
+    sphinx-autodoc-typehints
+allowlist_externals =
     rm
 commands =
-    sphinx-apidoc -o "./docs/" "keyosk"
-    rm "docs/modules.rst"
-    sphinx-build -M html "./docs/" "./docs/_build"
-    sphinx-build -M latex "./docs/" "./docs/_build"
+    sphinx-apidoc -o "{toxinidir}/docs/" "keyosk"
+    rm "{toxinidir}/docs/modules.rst"
+    sphinx-build -M html "{toxinidir}/docs/" "{toxinidir}/docs/_build"