MAINT simplified `setup.py`

  Unlike the version inherited from `scikit-learn` the new version
  requires Cython to be installed
MAINT use conda in `.travis.yml`
MAINT replaced C classifier for Cython
MAINT install Cython when running on Travis
Merge remote-tracking branch 'upstream/master'

Conflicts:
	setup.py
Ignore pycharm settings files