Skip generation of 'eo' files in i18n test suite

This PR disables the `test_generate` tests within the `rake i18n:test` suite.

@nedbat or @cpennington -- this is a request from a few engineers, that we don't run the extract, dummy, and generate tasks as part of `rake test`. I agree - I think we should run those tasks as part of Jenkins automation along with transifex pushes and pulls.

Edit: I changed it so we simply skip the generation of `'eo'` files.