Watching tests shouldn't restrict browser choices #96
Description
Currently, running tests has three options: Headless, Watch and All. I can do a headless test, which seems to be meant for CI environments. I can watch tests and the Chrome browser will open and continuously retest as I develop. All will test in both Chrome and Headless for a single run. There also the default, but that is just the Headless configuration. While convenient, his actually causes a few problems. First it assumes the developer has Chrome installed. I know it's preposterous to think someone doesn't have Chrome installed but at my normal job, there was a developer who was so Open Source oriented that he used Chromium instead of Chrome. We had to adjust our debugging process for him. Headless is a nice option since it can be installed with npm with no work from the developer. The all option uses the values in the karma config file and should be the default. Watching on the other hand should be option at all times. As such, you should move watching to a literal option which would produce:
ngl test <= would test against all browsers the karma config
ngl test headless <= would test against PhantomJs
ngl test --watch <= would test against all browsers in the karma config continuously
ngl test headless --watch <= would test against PhantomJs continuously
ngl test --browsers=Chrome,Firefox <= overrides the browsers to test with
ngl test --browsers=Chrome,Firefox --watch <= overrides the browsers to test with continuously
IMO, this gives us the best options for both a CI perspective and local testing.