Update Chef to the latest 10 and 11 releases

Also run tests using Ruby 2.1.1
Bump Chef client version for Chef 11
Fix coding style

That was easy thanks to rubocop
Fix more coding style issues
Ignore vendor directory in simplecov
Switch to RSpec 3

Also fix the coding style in more specs
Merge branch 'rspec3'
Make output not use unicode when stdout is not a TTY.

When using with Jenkins (etc), rather than fight it's UTF8/Unicode
support, just print the word "succees" rather the much cooler '✓'.

Yes, you could remove all the colours everywhere else too.