Add test to properly catch debian/sid strings from version

strings for wheezy/sid and jessie/sid aren't caught by the version number
 test already implmented.

Adds test to check if codename is still empty and version contains a slash
 if so, and minor is sid, we set codename to sid. Otherwise we set codename
 to major.

Adds test cases for platform_information to test expected usage patterns
 and covers some common os strings.

Futher assessment may then made to see if we should then refuse
 jessie or sid

Signed-off-by: Andrew Woodward <awoodward@mirantis.com>