fix(package): update npm to version 6.1.0

Closes #3

Author: greenkeeper[bot]

package.json

@@ -36,7 +36,7 @@
         "@types/uuid": "^3.4.3",
         "install": "^0.10.2",
         "nan": "^2.8.0",
-        "npm": "^5.6.0",
+        "npm": "^6.1.0",
         "ramda": "^0.25.0",
         "request": "^2.83.0",
         "request-promise": "^4.2.2",