message: Fix SHA for paper-button 3 golden.
diff: https://github.com/PolymerElements/paper-behaviors.git v2.0.1 paper-behaviors-2
  https://github.com/PolymerElements/paper-behaviors.git 28cf765323b8c7fe4440752968c651ccc1b16768 paper-behaviors-3
  https://github.com/PolymerElements/paper-button.git v2.0.0 paper-button-2
  -https://github.com/PolymerElements/paper-button.git e29e692e00839adcd94cfa08a3cd6b4165f3619e paper-button-3
  +https://github.com/PolymerElements/paper-button.git adb5fcb392287413b9b20bf7103014b8fffc76c9 paper-button-3
  https://github.com/PolymerElements/paper-menu-button.git v2.0.0 paper-menu-button-2
  https://github.com/PolymerElements/paper-menu-button.git 4dd8ac9107c25340b77c2ad27f8f11660eddb661 paper-menu-button-3
  https://github.com/Polymer/polymer.git 50ba80b864d4843d4e59cfdddeab6efdf280a2ec polymer-2
  