Add bin/bump alias
Add --version and --file/-f flags to bumpy

Fix #1
Change LOCALE messages
Limit one generated file per task

Also keep a reverse record so that a a generator can be
looked up by the file it produces
Look up file dependencies in the GENERATES table

Fix #4
Check arg length in bin/bump
Add Generic API
Update LOCALE names
Add file_requirements and task_requirements to _Task

They're populated when `requirements` is made, and each contain
exclusively files or exclusively tasks
Add arguments to help
Refactor LIST and DICT to a single TASKS dict
Clean up _Task code a bit
Alphabetize LOCALE
Privatize get_task, opts_to_dict, etc.
Rearrange and recomment some areas of bumpy.py
Reorganize decorators and add attributes
Add docstrings to everything
Convert bumpy.main into a private bumpy method
Update README.md
Merge branch 'dev'