Remove .js suffix in require paths

Remove the .js suffix in require paths to make requires consistent
across the project.

lib/clusterTools/index.js

@@ -12,5 +12,5 @@ module.exports = ({config} = {}) => ({
 		arg1 is the instanceID
 		Promise resolves with a string, either the displayName or instanceID if not found.
 	*/
-	getInstanceName: require("./getInstanceName.js")(config),
+	getInstanceName: require("./getInstanceName")(config),
 })