appsdk-bump-app-catalog 151 bumping sdk to 2720-73ffe87

sdk commit: RallySoftware/appsdk@bf6ec8672f81e5a52bd826f28cc3605909be5c2f
author: Matt Parrish and Steve Neely
message: No longer adding fetch=true query param to IoProvider.httpGet. It was preventing schema request from being cached.