fix FileConverter for new werkzeug

Merge pull request #99 from alexmojaki/ThreadingMixIn

Fix import of ThreadingMixIn for new werkzeug

No tox for make_release.sh

Merge pull request #95 from skeledrew/fix-string-exec

Fix source string exec

No more pycharm plugin

Merge pull request #90 from alexmojaki/fix-sqlalchemy

Fix after sqlalchemy 1.4