Two-Way Infinite Scroll Directive

![twis](https://cloud.githubusercontent.com/assets/1390651/5251861/97f9be12-794d-11e4-8512-240aa6459cc6.gif)

Fixes [MLHR-1596](https://malhar.atlassian.net/browse/MLHR-1596)

[Riders](http://en.wikipedia.org/wiki/Rider_(legislation)):
- Starting setup for e2e testing
- Made README more clear in install instructions
- cleaned up gulpfile
- added color style to dt-spinner when inside of a warning alert