Add tests for user satisfaction module
Deltas can have + prefixes too
Remove `npm start` script because it basically doesn't work

We are almost always going to want to provide command line args, which npm doesn't support
Merge pull request #40 from alphagov/feature/user-satisfaction

Add tests for user satisfaction module
Merge pull request #44 from alphagov/bugfix/npm-start-script

Remove `npm start` script because it basically doesn't work
Added binary executable