Bump all versions of dev dependencies and remove unused ones

package.json

@@ -32,21 +32,15 @@
   "homepage": "https://github.com/buunguyen/mongoose-deep-populate",
   "devDependencies": {
     "async": "^0.9.0",
-    "chai": "^1.9.2",
-    "event-stream": "^3.1.7",
-    "gulp": "^3.8.9",
+    "chai": "^2.1.1",
+    "gulp": "^3.8.11",
     "gulp-exit": "0.0.2",
-    "gulp-jshint": "^1.9.0",
-    "gulp-load-plugins": "^0.7.1",
-    "gulp-mocha": "^1.1.1",
-    "gulp-rename": "^1.2.0",
-    "gulp-util": "^3.0.1",
-    "jshint-stylish": "^1.0.0",
-    "lodash": "^2.4.1",
+    "gulp-jshint": "^1.9.2",
+    "gulp-load-plugins": "^0.8.1",
+    "gulp-mocha": "^2.0.0",
+    "jshint-stylish": "^1.0.1",
+    "lodash": "^3.4.0",
     "minimist": "^1.1.0",
-    "mocha": "^2.0.1",
-    "mongoose": "^3.8.23",
-    "sinon": "^1.11.1",
-    "stream-series": "^0.1.1"
+    "mongoose": "^3.8.24"
   }
 }