cloudfoundry/docs-deploying-cf — pull request #23 by philandstuff (2014-07-10 09:24:28+00:00)
Title: Don't install prerelease gems, they're way out of date

there hasn't been a prerelease version since 1.5.0.pre.1657 on
2013-12-27. The latest is 1.2624.0, released 2014-07-01.