Happy fails with python 3 default install

[tclarke]

Happy does not work with python 3.x but not not explicitly specify python 2 in the scripts so it will fail on a system where 'python' is 3.x. Fix should be to change the first lines of all scripts from #!/usr/bin/env python to #!/usr/bin/env python2

Ideally happy would be updated to support 3.x.