Fedora 21 release image, point fedora:latest to 21

The official fedora 21 image koji build can be found here:
http://koji.fedoraproject.org/koji/taskinfo?taskID=8289768

This commit also points fedora:latest to fedora:21

Update URLs to point to fedora-cloud account repo.

Signed-off-by: Lokesh Mandvekar <lsm5@fedoraproject.org>
Merge pull request #342 from fedora-cloud/fedora21-release

Fedora 21 release image, point fedora:latest to 21
cleanup fedora image repo Re: PR#342

Signed-off-by: Lokesh Mandvekar <lsm5@fedoraproject.org>
Bump jruby 1.7.17
Merge pull request #343 from fedora-cloud/fedora-21-release-2

cleanup fedora image repo Re: PR#342
Remove unreliable dev build

Building from the jruby git repo seems to try to pull artifacts from
other locations, which breaks every so often.
Merge pull request #344 from cpuguy83/bump_jruby_1.7.17

Bump jruby 1.7.17
Add new Travis stuff so PRs only test the bits that have changed
Merge pull request #345 from infosiftr/new-travis-magic

Add new Travis stuff so PRs only test the bits that have changed