Feature/setup protractor for testing

@bajtos 

Fixes #396
Are you sure protractor wants a config file for Karma integration tests? IIRC I am mentioning this problem for the third time now.

```
$ gulp test-client-e2e
[gulp] Using gulpfile ~/src/strong/studio/gulpfile.js
[gulp] Starting 'test-client-e2e'...
Studio running at http://localhost:9800
Running node_modules/.bin/protractor start --single-run --browsers PhantomJS client/test/integration/karma.integration.js
Usage: protractor [options] [configFile]
configFile defaults to protractor.conf.js
The [options] object will override values from the config file.
See the reference config for a full list of options.

Options:
  --help                                             Print Protractor help menu
  --version                                          Print Protractor version
  --browser, --capabilities.browserName              Browsername, e.g. chrome or firefox
  --seleniumAddress                                  A running selenium address to use
  --seleniumServerJar                                Location of the standalone selenium jar file
  --seleniumPort                                     Optional port for the selenium standalone server
  --baseUrl                                          URL to prepend to all relative paths
  --rootElement                                      Element housing ng-app, if not html or body
  --specs                                            Comma-separated list of files to test
  --exclude                                          Comma-separated list of files to exclude
  --verbose, --jasmineNodeOpts.isVerbose             Print full spec names
  --stackTrace, --jasmineNodeOpts.includeStackTrace  Print stack trace on error
  --params                                           Param object to be passed to the tests
  --framework                                        Test framework to use: jasmine, cucumber or mocha

Error: more than one config file specified
[gulp] Finished 'test-client-e2e' after 3.43 s
```

Please add `test-client-e2e` as a sub-task of the test task, so that `test` runs E2E tests too (it does not run them in the current version).

Consider renaming the task `mocha-and-karma` to `mocha-and-karma-and-protractor` and updating `npm test` script. It is important to have both "mocha" and "karma" in the task name, it's needed for our CI build tool.