Run travis against 4.2

[calebhearth]

While you're at it, Griddler has historically mimicked the supported versions for Ruby and Rails, so I think 4.0 might be able to be dropped, or it could be security only.

[gabebw]

Is 4.0 no longer officially supported?

[calebhearth]

Nope: http://guides.rubyonrails.org/maintenance_policy.html

[gabebw]

It looks like 4.1.x and 4.2.x are the only versions that have any support at all (and 3.2.x for security issues, but let's ignore that).

[calebhearth]

Agreed.