Remove direct dependency on rimraf. It's implicitly included by 'del' package.

Author: Matt Mazzola

package.json

@@ -61,7 +61,6 @@
     "merge2": "^1.0.1",
     "moment": "^2.14.1",
     "phantomjs-prebuilt": "^2.1.3",
-    "rimraf": "^2.5.1",
     "run-sequence": "^1.1.5",
     "ts-loader": "^0.8.1",
     "tslint": "^3.6.0",