Initial release

Co-authored-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Test coverage improvements

Signed-off-by: Jiri Kuncar <jiri.kuncar@gmail.com>
Documentation and code structure improvements

Signed-off-by: Jiri Kuncar <jiri.kuncar@gmail.com>
travis: install Flask-Menu from git
Fix for `register_menu` usage
Merge pull request #2 from jirikuncar/master

Fix for `register_menu` usage