Upgrade rake dependency from 0.9.2 -> 10
Upgrade rake dependency from 0.9.2 -> 10

This was a really old version to pin to. Upgrade so we're on the latest
version.

Change-Id: Ie2482e12f9552a89bad4728677a453e32095dd10
Reviewed-on: http://gerrit.causes.com/37004
Reviewed-by: Shane da Silva <6f6e68d1df92f30cb4b3ce35260ddf94a402f33d@causes.com>
Tested-by: Shane da Silva <6f6e68d1df92f30cb4b3ce35260ddf94a402f33d@causes.com>

tsubery/mock_redis,GearboxSoftware/mock_redis,batizhevsky/mock_redis,anujdas/mock_redis,brigade/mock_redis