remove autoload sprockets, it'll use our new auto_activation code

Gemfile

@@ -13,6 +13,9 @@ gem 'cucumber', '~> 1.3'
 gem 'contracts', '~> 0.4'
 
 # Optional middleman dependencies, included for tests
+gem 'haml', '>= 4.0.5', require: false
+gem 'coffee-script', '~> 2.2.0', require: false
+gem 'kramdown', '~> 1.2', require: false
 gem 'less', '2.3.0', require: false
 gem 'slim', '>= 2.0', require: false
 gem 'liquid', '>= 2.6', require: false
@@ -32,8 +35,5 @@ gem 'coveralls', '~> 0.7', require: false
 gem 'codeclimate-test-reporter', '~> 0.3', require: false, group: :test
 
 # Middleman itself
-gem 'middleman', path: 'middleman'
 gem 'middleman-cli', path: 'middleman-cli'
 gem 'middleman-core', path: 'middleman-core'
-gem 'middleman-compass',  github: 'middleman/middleman-compass', require: false
-gem 'middleman-sprockets', github: 'middleman/middleman-sprockets', require: false

middleman-core/lib/middleman-core/application.rb

@@ -158,9 +158,6 @@ module Middleman
       }
     }, 'Callbacks that can exclude paths from the sitemap'
 
-    config.define_setting :autoload_sprockets, true, 'Automatically load sprockets at startup?'
-    config[:autoload_sprockets] = (ENV['AUTOLOAD_SPROCKETS'] == 'true') if ENV['AUTOLOAD_SPROCKETS']
-
     attr_reader :config_context
     attr_reader :sitemap
     attr_reader :cache
@@ -213,15 +210,6 @@ module Middleman
 
       @extensions.auto_activate(:before_configuration)
 
-      if config[:autoload_sprockets]
-        begin
-          require 'middleman-sprockets'
-          @extensions.activate :sprockets
-        rescue LoadError
-          # It's OK if somebody is using middleman-core without middleman-sprockets
-        end
-      end
-
       run_hook :initialized
 
       run_hook :before_configuration

middleman-core/lib/middleman-core/renderers/markdown.rb

@@ -39,7 +39,7 @@ module Middleman
         rescue LoadError
           # If they just left it at the default engine and don't happen to have it,
           # then they're using middleman-core bare and we shouldn't bother them.
-          if config.setting(:markdown_engine).value_set?
+          if app.config.setting(:markdown_engine).value_set?
             logger.warn "Requested Markdown engine (#{app.config[:markdown_engine]}) not found. Maybe the gem needs to be installed and required?"
           end
         end