chore(package): update nsp to version 3.1.0

Closes #37

Author: greenkeeper[bot]

package.json

@@ -52,7 +52,7 @@
     "mocha": "^3.2.0",
     "nock": "9.0.13",
     "npm-run-all": "^4.0.2",
-    "nsp": "^2.6.3",
+    "nsp": "^3.1.0",
     "numeral": "^2.0.6",
     "open": "0.0.5",
     "rimraf": "2.6.1",