Added sorting and text field clearing.

* .gitignore ignores dist folder now
* Changed list of businesses mock to return unordered
  businesses
* Frontend now sorts the businesses
* After successful submission, text field for business name
  is cleared
Updated Dropwizard app to deployable version.

* Update taken from tomaszj/dropwizard-angular-sbt-for-heroku repository.
Added validation of a business name uniqueness.

* Added class names in businesses table to allow Selenium
  discoverability.
Removed test .jars from assembly step in build.sbt
Updated the API to respond with 409 whenever the business name already exists.
Updated Selenium tests.

* Added new test case for validation of business name uniqueness
* Removed some duplication in the test code