developer/bin/cask-pr-local-check: fix RuboCop style.

See https://github.com/Homebrew/brew/pull/7867.

developer/bin/cask-pr-local-check

@@ -1,12 +1,12 @@
 #!/usr/bin/env ruby
 
-require 'json'
-require 'open-uri'
-require 'optparse'
-require 'tmpdir'
+require "json"
+require "open-uri"
+require "optparse"
+require "tmpdir"
 
 # Options
-ARGV.push('--help') if ARGV.empty?
+ARGV.push("--help") if ARGV.empty?
 
 OptionParser.new do |opt|
   opt.banner = <<~BANNER
@@ -19,7 +19,7 @@ OptionParser.new do |opt|
     Options:
   BANNER
 
-  opt.on('-h', '--help', 'Show this help.') do
+  opt.on("-h", "--help", "Show this help.") do
     puts opt
     exit 0
   end
@@ -27,17 +27,20 @@ end.parse!
 
 pr_url = ARGV[0]
 
-abort 'URL is not from an official Homebrew Cask tap' if pr_url !~ %r{^https://github.com/Homebrew/homebrew-cask.*}
+unless %r{^https://github.com/Homebrew/homebrew-cask.*}.match?(pr_url)
+  abort "URL is not from an official Homebrew Cask tap"
+end
 
-pr_api = pr_url.sub(%r{^https://github.com/([^/]+)/([^/]+)/pull/([^/]+).*}, 'https://api.github.com/repos/\1/\2/pulls/\3/files')
+pr_api = pr_url.sub(%r{^https://github.com/([^/]+)/([^/]+)/pull/([^/]+).*},
+                    'https://api.github.com/repos/\1/\2/pulls/\3/files')
 pr_json = JSON.parse(URI(pr_api).read)
 
-abort 'PR needs to have a single file' if pr_json.count != 1
+abort "PR needs to have a single file" if pr_json.count != 1
 
-file_raw_url = pr_json[0]['raw_url']
+file_raw_url = pr_json[0]["raw_url"]
 file_name = File.basename(file_raw_url)
 local_file = File.join(Dir.mktmpdir, file_name)
 
 File.write(local_file, URI(file_raw_url).read)
-system('brew', 'cask', 'audit', '--download', local_file)
-system('brew', 'cask', 'style', local_file)
+system("brew", "cask", "audit", "--download", local_file)
+system("brew", "cask", "style", local_file)