Remove branch parameter for pre-existing badges

Badges still had branch parameter in URL for orginal branch instead of
using values from master.
Add Inch CI badge
Add CodeClimate badge
Add Gemnasium badge
Add rubygems badge
Merge branch 'master' into chore/badges
Fix version for branch
Merge pull request #19 from rapid7/chore/badges

Badges

Badges display correctly at https://github.com/rapid7/metasploit-model/tree/chore/badges so self-merging