Rename to Rake-n-bake

Fixes #6 by renaming the project to Rake n bake

- Gem name changes to `rake-n-bake`,  version set to `1.0.0`
- Tasks are namespaced under `:bake` for brevity
- Helpers are namespaced under `RakeNBake` for clarity
- Repo may still need renaming
Assuming the repo gets renamed too to `RichardVickerstaff/rake-n-bake`