feat: require Node.js >=10.13

BREAKING CHANGE: Require Node.js >= 10.13

lib/branches/index.js

@@ -50,7 +50,7 @@ module.exports = async (repositoryUrl, ciBranch, context) => {
   const duplicates = [...branches]
     .map(branch => branch.name)
     .sort()
-    .filter((val, idx, arr) => arr[idx] === arr[idx + 1] && arr[idx] !== arr[idx - 1]);
+    .filter((_, idx, arr) => arr[idx] === arr[idx + 1] && arr[idx] !== arr[idx - 1]);
 
   if (duplicates.length > 0) {
     errors.push(getError('EDUPLICATEBRANCHES', {duplicates}));