chore(deps): update dependency proxyquire to v2

Author: renovate-bot

package.json

@@ -48,7 +48,7 @@
     "hubot-test-helper": "1.8.1",
     "istanbul": "0.4.5",
     "mocha": "5.0.0",
-    "proxyquire": "1.8.0"
+    "proxyquire": "2.1.2"
   },
   "snyk": true
 }