Quilligan Quail Release

TT-1073 set up tox for gdc-ng-models (#6)

* TT-1073 set up tox for gdc-ng-models

* TT-1073 edited tox/travis files according to Jimmy's/Greg's comments

* feat(TT-1073): re-arrange tox commands

* fix(whoa): simplify

* fix(tox): small fix to tox to generalize py3

* fix(pr): pr issues fixed