move range and delay over to util module

src/util.js

@@ -0,0 +1,27 @@
+/*
+Copyright 2018 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+module.exports.range = function(start, amount, step = 1) {
+    const r = [];
+    for (let i = 0; i < amount; ++i) {
+        r.push(start + (i * step));
+    }
+    return r;
+}
+
+module.exports.delay = function(ms) {
+    return new Promise((resolve) => setTimeout(resolve, ms));
+}