Upgrade to minuteman 1.0.3 and test against Ruby 2.x

Upgrade to minuteman 1.0.3 and test against Ruby 2.x
Require minimum Rails 3, but allow 4.x also.

Now tests against MRI Rubies 1.9.3, 2.0, 2.1 and HEAD, and Rubinius 2.1 and 2.2.