Upgrade some dependencies, ignore files
Test newer ruby versions only
Skip 1.9.2 - travis can't perform :-(
Renames `enum` method in `renum`

active record 4.1 defines its own enum functionality. If you define your enums inside of your AR classes, the degu enums stop working, because they get overwritten by the AR method.
If the `enum` method does not exist yet, it will be aliased to `renum` on the 'rude include'.
Once is enough
Merge branch 'master' into large_sets