Consolidate all web projects on ruby 2.1.3

[kylef]

After discussion on Slack we can to the following conclusion:

• Travis to run 2.1.3
• Heroku to run 2.1.3
• Default locally to allow 2.0.0, but users with 2.1.3 will be able to use it

[floere]

@orta @kylef I think this is done. Confirm? Search is not on 2.1.3, because it's the cool kid on the block.

[orta]

Yeah