Fedora 22 reaches its EOL on 19-JUL-2016[1]. Remove it as
officially supported distribution.
The current two supported Fedora distributions are Fedora 23 and Fedora
24. (Change Ia4a58de4973ef228735c48b33453a0562dc65258 already added
support for Fedora 24.)
[1] https://fedoramagazine.org/fedora-22-end-of-life-2016-july/
Change-Id: I5b4e1ddb6165a9065e80e84175246678a7356f18