updated to Intern 2.1 and Selenium 2.43

Intern 2.1 resolves #144 and Selenium 2.43 resolves #145

In order to use Selenium 2.43, I had to replace grunt-se-launch w/ grunt-selenium-simple

On a side note, I can no longer run tests in Safari (since OSX Yosemite update?). I think it's related to this issue:

https://code.google.com/p/selenium/issues/detail?id=7933

I just can't be bothered w/ yet another Selenium browser driver issue.