Refactor reusable task methods, and allow update of local wiki
Abort if pulled wiki contains no features
Support nested wiki filenames.

Before, assumed wiki filenames like "thing.md", and would create "thing.feature"

Now detects filenames like "features > new_features > new_feature.feature.md",
and will create the directory "features/new_features", and plug the feature
content into the file "features/new_feature/new_feature.feature".

This addresses half of the requirements for #18 to be complete.
Respect branch specified in config
Remove no-longer necessary classes