Expands coverage of scripts linting, and improves checks for a correct
title. Various fixes to make 'python travis/all.py' work for offline
users; when the TRAVIS envvar is not set it now fails without an error.
Minor cleanup in conf.py
The change to pr-check-base avoids failing builds which should pass
because the GH API is limited. It'll still work almost all of the time,
but no longer fail builds which previously passed and then pushed more
commits. Closes#694.
PeridexisErrant