Update dependency child-process-promise to v^2.0.0

Author: renovate[bot]

package.json

@@ -28,7 +28,7 @@
   "homepage": "https://github.com/lgaticaq/docker-scanimage#readme",
   "dependencies": {
     "bluebird": "^3.1.4",
-    "child-process-promise": "^1.1.0",
+    "child-process-promise": "^2.0.0",
     "core-worker": "^0.3.0",
     "imagemagick": "^0.1.3",
     "imgur": "^0.1.7",