small adjusments

Gemfile

@@ -16,7 +16,7 @@ gem 'rspec', '~> 3.0'
 gem 'cucumber', '~> 2.0'
 gem 'capybara', '~> 2.5.0'
 gem 'haml', '< 7'
-gem 'slim', '< 5'
+gem 'slim', '>= 3', '< 5'
 gem 'kramdown'
 gem "redcarpet"
 

README.md

@@ -196,7 +196,7 @@ The best way to get quick responses to your issues and swift fixes to your bugs
 
 ## Donate
 
-[Click here to lend your support to Middleman](https://spacebox.io/s/4dXbHBorC3)
+[Click here to lend your support to Middleman](https://github.com/sponsors/tdreyno)
 
 ## License
 
@@ -205,6 +205,4 @@ Copyright (c) 2012-2014 Benjamin Hollis. MIT Licensed, see [LICENSE] for details
 [middleman]: http://middlemanapp.com
 [gem]: https://rubygems.org/gems/middleman-syntax
 [travis]: http://travis-ci.org/middleman/middleman-syntax
-[gemnasium]: https://gemnasium.com/middleman/middleman-syntax
-[codeclimate]: https://codeclimate.com/github/middleman/middleman-syntax
 [LICENSE]: https://github.com/middleman/middleman-syntax/blob/master/LICENSE.md