environment is an overloaded term. Don't use it

It could be 'staging' or 'production' and describe how many boxes it's
on, or it could be something to do with the availablility.

Provider zone might want splitting out. Possibly we could use the same
terms as salt-cloud: provider (aws, vcloud) and profile.
Update to use .cotton.yaml, cotton.yaml and project.yaml

To make the configuration files more easy to trace through the
names of the config files are made a bit more precise.
All of the existing config filenames are still valid but
it will generate a warning about deprecated naming if they
are found.
Update README.md
renaming variables
better output and fixed empty initial file case
Merge pull request #1 from ministryofjustice/avoid-overloaded-terms

Update to use .cotton.yaml, cotton.yaml and project.yaml