Replace form field widgets with a class, not class instance

[alexey-v-paramonov]

No description provided.

[coloradocarlos]

@alexey-v-paramonov Can you bump up the version number to 0.14.1? Otherwise get this warning with pip on CircleCI (also local environment):

Collecting git+git://github.com/alexey-v-paramonov/formly@master (from -r requirements/base.txt (line 34))
  Cloning git://github.com/alexey-v-paramonov/formly (to master) to /tmp/pip-n3rHLT-build
  Requirement already satisfied (use --upgrade to upgrade): formly==0.14.0 from git+git://github.com/alexey-v-paramonov/formly@master in ./venv/lib/python2.7/site-packages (from -r requirements/base.txt (line 34))

[grahamu]

FYI @coloradocarlos @alexey-v-paramonov I'm actively working on a new formly release in #33. I'll be sure to include this PR and let you know of the new published version on PyPi when I'm done. New release uses namespacing, revised URL names, and contains an expanded test suite.

[jacobwegner]

Thanks for the fix and test, @alexey-v-paramonov.

Since the newest release will be BI, @grahamu and I have decided to pull this in to a bugfix release.