bump electron to 4.2.6

CONTRIBUTING.md

@@ -94,7 +94,7 @@ docker build -t "$DOCKER_ORCA_IMAGE" -f deployment/Dockerfile .
 To run the image tests, run the following:
 ```
 ./test/image/render_mocks_cli build/test_images "$DOCKER_ORCA_IMAGE" && \
-./test/image/compare_images test/image/baselines build/test_images build/
+./test/image/compare_images test/image/baselines build/test_images build/test_images_diff
 ```
 
 #### Generate new baselines

README.md

@@ -31,7 +31,7 @@ If you have Node.js installed (recommended v8.x), you can easily install Orca
 using npm as:
 
 ```
-$ npm install -g electron@1.8.4 orca
+$ npm install -g electron@4.2.6 orca
 ```
 
 which makes the `orca` executable available in your path.

package.json

@@ -88,7 +88,7 @@
     "chttps": "^1.0.6",
     "cross-env": "^5.2.0",
     "devtron": "^1.4.0",
-    "electron": "^1.8.4",
+    "electron": "^4.2.6",
     "electron-builder": "^20.9.2",
     "electron-debug": "^1.4.0",
     "image-size": "^0.6.3",