Abstract away update method to support more tools

Abstract away update method inside an interface so that other tools
similar to repo can be supported.

Change-Id: I4964e0f9f89b4a02ce1cd7bb2cdcffb6cf24f585
7 files changed
tree: c3d82e4a67a1aee7753ef2232b68cc7edb8597c8
  1. BUILD
  2. LICENSE
  3. src/