Upgrade dev dependencies

Including multiple major version upgrades.

// FREEBIE

package.json

@@ -14,18 +14,18 @@
     "bower": "^1.3.12",
     "electron": "^1.6.1",
     "electron-builder": "^16.4.2",
-    "grunt": "^0.4.5",
+    "grunt": "^1.0.1",
-    "grunt-cli": "^0.1.13",
+    "grunt-cli": "^1.2.0",
-    "grunt-contrib-concat": "^0.5.0",
+    "grunt-contrib-concat": "^1.0.1",
-    "grunt-contrib-connect": "^0.9.0",
+    "grunt-contrib-connect": "^1.0.2",
-    "grunt-contrib-copy": "^0.8.0",
+    "grunt-contrib-copy": "^1.0.0",
     "grunt-contrib-jshint": "^1.1.0",
-    "grunt-contrib-sass": "^0.8.1",
+    "grunt-contrib-sass": "^1.0.0",
-    "grunt-contrib-watch": "^0.6.1",
+    "grunt-contrib-watch": "^1.0.0",
-    "grunt-exec": "^0.4.6",
+    "grunt-exec": "^2.0.0",
     "grunt-gitinfo": "^0.1.7",
-    "grunt-jscs": "^1.1.0",
+    "grunt-jscs": "^3.0.1",
-    "grunt-saucelabs": "^8.3.3",
+    "grunt-saucelabs": "^9.0.0",
     "icon-gen": "^1.0.7"
   },
   "scripts": {