This will allow us to address any deprecations and incompatibilities
before new versions of Rails are released, making it easier for folks to
upgrade their applications.
I am ignoring the gemfile.lock here because I want CI to always run
against the latest master, not a specific commit.
I am allowing failures on Travis because I don't want these failures to
block people's PRs (like what we do with ruby-head).
to run rubocop locally and not to wait for HoundCI to bark at us.
The version is locked to 0.54 because this is the version HoundCI is using.
Using a newer version will not work as config changed from 0.54 to currently 0.59
and rubocop would complain with the old configuration.
thoughtbot uses the .rubocop.yml in thoughtbot/guides
as the orginizational config on Hound, so we inherit
from it so we can use the same config locally.
Fix#1195.
