move plugin gem

Gemfile

@@ -16,6 +16,7 @@ gem "minima", "~> 2.5"
 # If you have any plugins, put them here!
 group :jekyll_plugins do
   gem "jekyll-feed", "~> 0.12"
+  gem "jekyll-remote-theme", "~> 0.4.3"
 end
 
 # Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem
@@ -31,5 +32,3 @@ gem "wdm", "~> 0.1.1", :platforms => [:mingw, :x64_mingw, :mswin]
 # Lock `http_parser.rb` gem to `v0.6.x` on JRuby builds since newer versions of the gem
 # do not have a Java counterpart.
 gem "http_parser.rb", "~> 0.6.0", :platforms => [:jruby]
-
-gem "jekyll-remote-theme", "~> 0.4.3"