add a normalized_release function

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>
tests for the new normalizer for versions

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>
Merge pull request #229 from ceph/wip-9045

add a normalizer for distro versions
Updates to the install.py rpm_dist() and repository_url_part() to remove type casting and using the native ints in the normalized_release object.
Signed-off-by: Tom Walsh <tom.walsh@expresshosting.net>
Merge branch 'master' of https://github.com/tomwalsh/ceph-deploy
Merge remote-tracking branch 'upstream/master'