Godeps/_workspace/src/gopkg.in/mgo.v2/session.go
func (c *Collection) DropCollection() error {
	return c.Database.Run(bson.D{{"drop", c.Name}}, nil)
}
func (c *Collection) DropCollection() error {
	return c.Database.Run(bson.D{{"drop", c.Name}}, nil)
}
// DropCollection removes the entire collection including all of its documents.