message: Move testbed back to electron 1.6.11
diff: "@bentley/imodeljs-clients": "^1.0.36",
  "@bentley/imodeljs-nodeaddonapi": "^1.2.0",
  "body-parser": "^1.18.2",
  - "electron": "^1.8.1",
  + "electron": "^1.6.11",
  "express": "^4.16.2",
  "floss": "^2.1.3",
  "fs-extra": "^4.0.3",
  