Travis tests failing with Python 3.7

[jrwdunham]

Two tests are failing in Python 3.7 that are not failing in Py 3.5 and 3.6:

• old/tests/functional/test_forms.py::TestFormsView::test_create FAILED
• old/tests/functional/test_forms.py::TestFormsView::test_morphemic_analysis_compilation FAILED

The Pylint linting is also failing in the Py 3.7 build with StopIteration errors. This (closed) issue may be related: pylint-dev/pylint#2241.