Add Karma as Test runner

Closes #39.
More work on Karma integration, still WIP
Fix Jasmine tests in use with RequireJS
Get Karma working with RequireJS implementation - Jasmine fails

Currently Jasmine fails since we don't use a baseUrl in
js/config.js. If we set a baseUrl we overwrite what is defined in
tests/test-main.js.
Install global npm modules in Travis CI in one line
Remove Jasmine task from Grunt

We run tests with Karma and thus don't need the Jasmine task
anymore.
Add karma.conf.js file with default configuration
Use module variable in JS example module to fix JSHint
Use Phantom and Firefox for Karma on Travis
Merge branch 'karma' into v1.0.0

This implements a Grunt task for the Karma test-runnter.

Closes #39.