Bug 1750948: upgrading dependencies to work with latest node 8.x (LTS)

You may need to update node via:
sudo npm cache clean -f
sudo npm install -g n
sudo n 8.11.3 (latest at patch)

Then update node-sass bindings:
sudo npm rebuild node-sass

behatnotneeded

Change-Id: I18d1dc9d90bd56fa0d16837d2bf6e4c19c9662ba

package.json

@@ -9,17 +9,18 @@
   },
   "license": "GPL-3.0",
   "dependencies": {
-    "gulp": "^3.9.1",
+    "es6-promise": "^4.2.4",
+    "event-stream": "^3.3.4",
+    "globule": "^1.0.0",
+    "gulp": "<=3.9.1",
+    "gulp-autoprefixer": "^5.0.0",
     "gulp-clean-css": "^3.0.2",
-    "gulp-sass": "^2.3.2",
     "gulp-help": "^1.6.1",
+    "gulp-if": "^2.0.2",
+    "gulp-sass": "^4.0.1",
+    "node-sass": "<=4.8.3",
     "path": "^0.11.14",
-    "event-stream": "^3.3.4",
-    "globule": "^1.0.0",
-    "gulp-autoprefixer": "^3.1.1",
-    "es6-promise": "^3.2.1",
-    "yargs": "^3.27.0",
-    "gulp-if": "^2.0.1"
+    "yargs": "^11.0.0"
   },
   "devDependencies": {},
   "scripts": {