installing python libs

parts:
   flask:
      plugin: python2
      source: https://github.com/mitsuhiko/flask.git
      source-type: git
   tornado:
      plugin: python2
      source: https://github.com/tornadoweb/tornado.git
      source-type: git
   yaml:
      plugin: python2
      source: https://github.com/ravenac95/PyYAML.git
      source-type: git