I have found a way to integrate August Lock into SmartThings (although it is a bit wonky). I am using a memo switch and the Yonomi app on iOS. As we know, WeMo can be controlled directly from smartthings. Using Yonom, I created a routine that looks for a Wemo switch and controls the lock. When the Wemo switch is powered on the routine runs and unlocks the August. When the switch is powered off the routine locks the lock.
In practice I have found it works well under the following conditions:
the phone running the yonomi app must be connected to the lock via bluetooth. I have yet to experiment whether or not it works via august connect. For best results I have had the august app and the yonomi app running in the background.
I am considering stationing an older phone near the door to act as a gateway amongst the systems.