ENYO-2877: Updated README.md about automatic execution of jshint on pull-request submission.

Enyo-DCO-1.1-Signed-off-by: Yves Del Medico <yves.del-medico@hp.com>
Merge pull request #7 from enyojs/ENYO-2877

ENYO-2877: Updated README.md about automatic execution of jshint on pull...