Minor ES6 improvements

Change-Id: Ibf956915d1b7769dc5cc22a870f4484f492da723
diff --git a/dev/js/src/match/table.js b/dev/js/src/match/table.js
index 4f8abcc..969de77 100644
--- a/dev/js/src/match/table.js
+++ b/dev/js/src/match/table.js
@@ -121,7 +121,8 @@
               found[foundry + "/" + layer] = [value];
             }
             else {
-              if (found[foundry + "/" + layer].indexOf(value) === -1) {
+              // if (found[foundry + "/" + layer].indexOf(value) === -1) {
+              if (!found[foundry + "/" + layer].includes(value)) {
                 // Push value to foundry/layer at correct position
                 found[foundry + "/" + layer].push(value);
               };