Add source reference
Merge branch 'master' of https://github.com/CollectionFS/Meteor-powerqueue

# By Morten N.O. Nørgaard Henriksen
# Via Morten N.O. Nørgaard Henriksen
* 'master' of https://github.com/CollectionFS/Meteor-powerqueue:
  Update api.md

Conflicts:
	api.md