A new validation check:

* validate_count_as_odd_for_role
  As the name describes we want to check that we have an odd number
  of nodes used in a role.

Signed-off-by: JuanJose 'JJ' Galvez <jj.galvez@inktank.com>
Must specify the version being used for the activesupport gem.
If the version is not specificed it tries the newest which we
can not support on Roxy due to the ruby version in use.

2.3.17 is what is available on the admin server.

Signed-off-by: JuanJose 'JJ' Galvez <jj.galvez@inktank.com>
Added chef without version to Gemfile again
Made the edit deployment partial optional

(cherry picked from commit 126372f2e385024da705b382ee96ae87bc3e9b2c)
Improve comment about new role_constraints

(cherry picked from commit d1b2b4506bdc6d12c37e8bbe8753a10b58b2305a)
Merge pull request #971 from tboerger/feature/roxy/gemfile-chef

[roxy] Added chef without version to Gemfile again
Merge pull request #974 from vuntz/release/roxy/master

Backport the role_constraints bit to roxy
Merge pull request #965 from jgalvez/feature/wip-roxy-bluepill-deploy-fix/master

Fix: Must specify the version being used for the activesupport gem.
Merge pull request #963 from jgalvez/pull-req-release-roxy-master-5458bf315d94064341d4731918096a43df5e57ae

Check for odd number of ceph-mon in proposal [1/2]
Merge pull request #970 from vuntz/constraint-validation

Add proposal validation based on constraints