Update dependencies to fix installation

package.json

@@ -19,26 +19,26 @@
     "url": "git://github.com/hakimel/reveal.js.git"
   },
   "engines": {
-    "node": "~0.10.0"
+    "node": "~4.1.1"
   },
   "dependencies": {
-    "underscore": "~1.5.1",
-    "express": "~2.5.9",
-    "mustache": "~0.7.2",
-    "socket.io": "~0.9.16"
+    "underscore": "~1.8.3",
+    "express": "~4.13.3",
+    "mustache": "~2.1.3",
+    "socket.io": "~1.3.7"
   },
   "devDependencies": {
-    "grunt-contrib-qunit": "~0.5.2",
-    "grunt-contrib-jshint": "~0.6.4",
-    "grunt-contrib-cssmin": "~0.12.2",
-    "grunt-contrib-uglify": "~0.2.4",
-    "grunt-contrib-watch": "~0.5.3",
-    "grunt-sass": "~0.14.0",
-    "grunt-contrib-connect": "~0.8.0",
-    "grunt-autoprefixer": "~1.0.1",
-    "grunt-zip": "~0.7.0",
-    "grunt": "~0.4.0",
-    "node-sass": "~0.9.3"
+    "grunt-contrib-qunit": "~0.7.0",
+    "grunt-contrib-jshint": "~0.11.3",
+    "grunt-contrib-cssmin": "~0.14.0",
+    "grunt-contrib-uglify": "~0.9.2",
+    "grunt-contrib-watch": "~0.6.1",
+    "grunt-sass": "~1.1.0-beta",
+    "grunt-contrib-connect": "~0.11.2",
+    "grunt-autoprefixer": "~3.0.3",
+    "grunt-zip": "~0.17.1",
+    "grunt": "~0.4.5",
+    "node-sass": "~3.3.3"
   },
   
   "license": "MIT"