let's try ruby 2.1
well try 2.1.0 then
Update Bundler on travis for ruby 2.1
Revert "Update Bundler on travis for ruby 2.1"

apparently we don't need that anymore
fixes segfaults caused by stubbing
lessen test ramp-up
Merge pull request #777 from opf/feature/ruby2.1

let's try ruby 2.1