Adding build status icon to README.md.
Adding build status icon to README.md.

phase2/grunt-drupal-tasks,EvanLovely/grunt-drupal-tasks,puppetlabs/grunt-drupal-tasks,puppetlabs/grunt-drupal-tasks,AndBicScadMedia/grunt-drupal-tasks,AndBicScadMedia/grunt-drupal-tasks,puppetlabs/grunt-drupal-tasks,EvanLovely/grunt-drupal-tasks,phase2/grunt-drupal-tasks,AndBicScadMedia/grunt-drupal-tasks,phase2/grunt-drupal-tasks,puppetlabs/grunt-drupal-tasks,EvanLovely/grunt-drupal-tasks,AndBicScadMedia/grunt-drupal-tasks,EvanLovely/grunt-drupal-tasks