BLD: remove pypy (python-apt)
BLD: update VERSION.txt: 0.1.2
Bug: VERSION.txt os.path.basename
DOC: API docs: docs/modules.rst docs/pkgsetcomp.rst
BLD,CLN: remove __pycache__ in 'make clean-build'
Merge branch 'hotfix/0.1.2'

* hotfix/0.1.2:
  BLD,CLN: remove __pycache__ in 'make clean-build'
  DOC: API docs: docs/modules.rst docs/pkgsetcomp.rst
  Bug: VERSION.txt os.path.basename
  BLD: update VERSION.txt: 0.1.2
  BLD: remove pypy (python-apt)