Remove duplicate concat-stream dependency

Author: jfirebaugh

package.json

@@ -48,7 +48,6 @@
   },
   "devDependencies": {
     "chdir": "0.0.0",
-    "concat-stream": "^1.4.7",
     "eslint": "^1.5.1",
     "glob": "^5.0.2",
     "lodash": "^3.10.1",