Fix for OC-11422

No longer allow single integer version numbers for dependencies on the server side.

Please see [OC-11422](https://tickets.corp.opscode.com/browse/OC-11422) for more information.

Tests: https://github.com/opscode/chef-pedant/pull/74
I guess the example should change to be: `(1.0 is the same as 1.0.0)` since now just `1` is not valid?