Travis support for rails/ar 4.0, 4.1 and 4.2

[toxix]

This adds sepperate gemfiles for all actualy released versions of rails 4 and active record 4. It also support ruby 2.2.

you may prefere merging this over the minor changes from #62 or #61

[toxix]

Don't know wat to do with the failing installation of gems when activrecord/rails is used with jruby-19mode

[ryedog]

the issue is the new statement cache in ActiveRecord 4.2.

It doesn't ask for a scope unless skip_statement_cache? returns true
and skip_statement_cache? returns false unless there is already a scope
but since protector is dynamically adding the scope on request of the scope there is not scope at the time skip_statement_cache? is called.

there's a simple fix (although a little rough to hunt down) https://github.com/Updater/protector/pull/2/files