addStep now returns the tour for easier chaining
addStep now returns the tour for easier chaining

See https://github.com/HubSpot/shepherd/pull/18 for full conversation

Planwise/shepherd,haidaxiaocong/--,dieface/shepherd,mcanthony/shepherd,jasonpang/shepherd,GerHobbelt/shepherd,HubSpot/shepherd,ministrycentered/shepherd