Electron: install bower devDependencies for electron build

Fixes #1028

package.json

@@ -34,9 +34,9 @@
     "protractor": "protractor test/protractor-conf.js",
     "premake-local": "bower install --dev",
     "make-local": "make -f electron.makefile uselocal",
-    "build-electron-windows": "make -f electron.makefile build-electron-windows",
-    "build-electron-darwin": "make -f electron.makefile build-electron-darwin",
-    "build-electron-linux": "make -f electron.makefile build-electron-linux",
+    "build-electron-windows": "make -f electron.makefile bower build-electron-windows",
+    "build-electron-darwin": "make -f electron.makefile bower build-electron-darwin",
+    "build-electron-linux": "make -f electron.makefile bower build-electron-linux",
     "update-index-async": "node -e \"require('shelljs/global'); sed('-i', /\\/\\/@@NG_LOADER_START@@[\\s\\S]*\\/\\/@@NG_LOADER_END@@/, '//@@NG_LOADER_START@@\\n' + cat('app/bower_components/angular-loader/angular-loader.min.js') + '\\n//@@NG_LOADER_END@@', 'app/index-async.html');\""
   }
 }