Loosened ruby version requirement

[venkatd]

We want to allow a less strict ruby version requirement, just ruby 2.1, and still allow this to pass on Travis.

[begedin]

Are we absolutely sure this is possible?

From what I can tell, Travis wants us to specify a ruby version (or multiple ruby versions) to test against. We can't tell him to "test against one of these", though.

Likewise, bundler doesn't seem to support specifying a range of ruby versions, only one specific version. There seems to be a desire to go in that direction, but I don't see it implemented yet. There are two open issues I found related to this - rubygems/bundler#2845 and rubygems/bundler#2778

[venkatd]

Closing this. Let us just make sure the code gem is kept up to date with the latest ruby. We'll just have to stay on the cutting edge with our global ruby version.