Fix rubocop offenses in exe/jekyll

.rubocop.yml

@@ -4,7 +4,6 @@ AllCops:
   Include:
   - lib/**/*.rb
   Exclude:
-  - exe/jekyll
   - lib/jekyll/collection.rb
   - lib/jekyll/command.rb
   - lib/jekyll/configuration.rb

exe/jekyll

@@ -1,33 +1,37 @@
 #!/usr/bin/env ruby
 STDOUT.sync = true
 
-$LOAD_PATH.unshift File.join(File.dirname(__FILE__), *%w( .. lib ))
+$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), *%w( .. lib )))
 
-require 'jekyll'
-require 'mercenary'
+require "jekyll"
+require "mercenary"
 
 Jekyll::PluginManager.require_from_bundler
 
 Jekyll::Deprecator.process(ARGV)
 
 Mercenary.program(:jekyll) do |p|
   p.version Jekyll::VERSION
-  p.description 'Jekyll is a blog-aware, static site generator in Ruby'
-  p.syntax 'jekyll <subcommand> [options]'
-
-  p.option 'source', '-s', '--source [DIR]', 'Source directory (defaults to ./)'
-  p.option 'destination', '-d', '--destination [DIR]', 'Destination directory (defaults to ./_site)'
-  p.option 'safe', '--safe', 'Safe mode (defaults to false)'
-  p.option 'plugins_dir', '-p', '--plugins PLUGINS_DIR1[,PLUGINS_DIR2[,...]]', Array, 'Plugins directory (defaults to ./_plugins)'
-  p.option 'layouts_dir', '--layouts DIR', String, 'Layouts directory (defaults to ./_layouts)'
-  p.option 'profile', '--profile', 'Generate a Liquid rendering profile'
+  p.description "Jekyll is a blog-aware, static site generator in Ruby"
+  p.syntax "jekyll <subcommand> [options]"
+
+  p.option "source", "-s", "--source [DIR]", "Source directory (defaults to ./)"
+  p.option "destination", "-d", "--destination [DIR]",
+    "Destination directory (defaults to ./_site)"
+  p.option "safe", "--safe", "Safe mode (defaults to false)"
+  p.option "plugins_dir", "-p", "--plugins PLUGINS_DIR1[,PLUGINS_DIR2[,...]]", Array,
+    "Plugins directory (defaults to ./_plugins)"
+  p.option "layouts_dir", "--layouts DIR", String,
+    "Layouts directory (defaults to ./_layouts)"
+  p.option "profile", "--profile", "Generate a Liquid rendering profile"
 
   Jekyll::External.require_if_present(Jekyll::External.blessed_gems) do |g|
-    cmd = g.split('-').last
+    cmd = g.split("-").last
     p.command(cmd.to_sym) do |c|
       c.syntax cmd
       c.action do
-        Jekyll.logger.abort_with "You must install the '#{g}' gem to use the 'jekyll #{cmd}' command."
+        Jekyll.logger.abort_with "You must install the '#{g}' gem" \
+          " to use the 'jekyll #{cmd}' command."
       end
     end
   end