Cleanup of e2e test HTML and http-mock

- Making http-mock its own module to inject into "testapp"
- Removing unnecessary "getAdditionalParams" scope function from test app in e2e test HTML
- spreadsheet-controls-http-mock.js can now be loaded prior to "testapp" module
- Removing blank lines
Merge pull request #24 from stulees/feature/mock-e2e-tests

Cleanup of e2e test HTML and http-mock