chore(package): update prebuild-install to version 2.1.1

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -14,7 +14,7 @@
   "license": "MIT",
   "dependencies": {
     "builddependencies": "^0.0.1",
-    "prebuild-install": "^2.1.0"
+    "prebuild-install": "^2.1.1"
   },
   "buildDependencies": [
     "download-manager",