fix path for ext dangerfile

Author: lucas-zimerman

danger/dangerfile.js

@@ -197,7 +197,7 @@ async function CheckFromExternalChecks() {
   if (customPath) {
     try {
 
-      const extraModule = require(customPath);
+      const extraModule = require("./" + customPath);
 
       if (typeof extraModule === "function") {
         await extraModule({