Fix broken test suite in IE8

There was a little too much ES5 in the test suite.
Update travis.ci url in README

It definitely wasn't copied from another project. No. Definitely not.
Merge pull request #3 from aron/fix-ie8-tests

Fix broken test suite in IE8
Open the popup window centered in the browser window

Previously it would open in the center of the screen which was
disorientating. Now it appears in the center of the browser window.
Merge pull request #4 from aron/center-window

Open the popup window centered in the browser window
Add versioning script
Add documentation about the version script
v1.0.0