Move require call to own method

[adam12]

I normalized both calls to Kernel.send(options[:method], file) into their own method.

Right or wrong, I need to monkeypatch this method to support the auto_reloader gem, which uses Object.require and not Kernel.require.

It would be great to push this further, where a callable object with filename could be provided, instead of presuming a method on Kernel would be called. I might submit a PR for this if there is interest.

Much thanks.

[coveralls]

Coverage decreased (-1.5%) to 96.436% when pulling 44aa0b0 on adam12:require-separate-method into 85f7d85 on jarmo:master.

[jarmo]

Merged and released version 1.5.0. Thanks!