Bumped version to 6.2.0.rc1
hydra-head upgraded to ~> 6.5.0
rubydora upgraded to ~> 1.7.4

Upgraded active-fedora to ~> 6.7.7
Merge pull request #46 from dchandekstark/hydra-6-2-0-rc1

Bumped version to 6.2.0.rc1