(HI-285) Remove saucy from build defaults

This commit removes saucy from build defaults, it went EOL July 17, 2014
(maint) Pull out Sid and Unstable

This commit pulls out Sid and Unstable from build_defaults, they are no
longer supported.
Merge pull request #207 from clantant/HI-285/stable/saucy

(HI-285 & maint) update build defaults
Merge remote-tracking branch 'upstream/stable'

* upstream/stable:
  (maint) Pull out Sid and Unstable
  (HI-285) Remove saucy from build defaults

Conflicts:
	ext/build_defaults.yaml