fixes #43; update intern to 1.5 and add grunt tests & update docs

  - run `grunt test:'target'` where target is local or remote
  - add any reporters via flags e.g. `grunt test:local:console`, usage is provided via `grunt --help`
Note: there's multiple test failures in deliteful currently before and after the grunt changes, locally and in sauce, I'll update the PR with comments

You'll need to `npm update` to upgrade to intern 1.5 
***
I took a while committing this because I saw many test failures, so I switched back and forth between master and my branch to make sure I wasn't introducing new issues. 
My opinion is at this point in time the deliteful tests are *very* messy. 
I'm confident I've introduced no regressions however I'd like to highlight some tasks we need to take forward (maybe belonging in a separate issue?)

* Confirm the environments we need to be testing against. I raised https://github.com/ibm-js/delite/issues/118 and that needs to be converted to a full saucelabs environments configuration
* Normalise intern.js environments so that delite and deliteful match. I'd think whatever environments deliteful supports, delite supports too. Therefore intern.js environments need to be the same.
* Committers need to run a full saucelabs/remote test to confirm there are no regressions with their tests before committing
* I didn't try running the android/ios tests because the desktop tests were causing so many failures, we should comment those out till we're sure tests run in all the expected desktop browsers first