General idea is to use classmethod for every constructor and
statismethod otherwise.
Also use self and cls whenever it's possible to call static and class
methods
* add models tests (#1)
also replace single quote to double one to confort PEP docstring
+ move _check_output to class properties to make it available for
mocking
* alpm tests implementation
* try to replace os with pathlib
* update tests for pathlib
* fix includes glob and trim version from dependencies
* build_tools package tests
* repository component tests
* add sign tests
* complete status tests
* handle exceptions in actual_version calls
* complete core tests
* move configuration to root conftest
* application tests
* complete application tests
* change copyright to more generic one
* base web tests
* complete web tests
* complete testkit
also add argument parsers test