Rakefile in dispatch-rider-2.1.0 vs Rakefile in dispatch-rider-2.2.0

@@ -1,14 +1,15 @@
 # encoding: utf-8
+# frozen_string_literal: true
 
 require 'rubygems'
 
 begin
   require 'bundler'
 rescue LoadError => e
   warn e.message
   warn "Run `gem install bundler` to install Bundler."
-  exit -1
+  exit(-1)
 end
 
 begin
   Bundler.setup(:development)
 rescue Bundler::BundlerError => e