Rename executable

So it is a verb as per all the other tools.

Also make it executable - it should have been already and somehow worked anyway without being - possibly to do with some rbenv magic.
Add methadone

All code is in bin file. This is incorrect - it should be similar to https://github.com/jimweirich/rake/blob/master/bin/rake, outside and tested.
Make bin actually do the work
Bump version for CLI
Add command to README

Plus note that rest of it is out of date.
Merge pull request #16 from alphagov/temp-cli

[#64583408] Temp cli