Extract performer class for rake tasks

[Melanitski]

For fixing issue #94
Can you apply it, please?

[coveralls]

Coverage remained the same when pulling 9480298 on Rademade:master into 0c298d9 on 42dev:master.

[coveralls]

Coverage remained the same when pulling 95cdec0 on Rademade:master into 0c298d9 on 42dev:master.

[SergeyKishenin]

Is it going in addition to configurable root_path feature?

Also, resolve_asset_paths and remove_extra_files methods for related rake tasks won't work, I guess.

[Melanitski]

It isn't addition, it would have few conflicts. I can slove it.

[Melanitski]

What we can fix for merge your pull request?
It's very important to your gem. Thanks

[SergeyKishenin]

Well, you can merge issue-94 branch and depend everywhere on BowerRails.root_path.

Also, as I said before there is something wrong with resolve_asset_paths and remove_extra_files methods. Now you call only perform instance method in perform class one. So

BowerRails::Performer.perform false do
  resolve_asset_paths
end

won't work, right?

This should be fixed too. Thanks.

[coveralls]

Coverage increased (+0.14%) when pulling 0babdaf on Rademade:master into 0c298d9 on 42dev:master.

[coveralls]

Coverage increased (+0.14%) when pulling 8f37e8d on Rademade:master into 0c298d9 on 42dev:master.

[Melanitski]

Already merged issue-94 to master
Also fix methods resolve_asset_paths and remove_extra_files in performer.

Could you apply pull request and update gem version please?

[SergeyKishenin]

Thanks!