Use similar interface to access gitolite

Simplified gitolite handle logic
Stubn over monkeypatch
Stub only specific methods in Gitlab:Gitolite
Moved grach auth to lib
added specs for keys observer
removes SshKey role

lib/gitlab/backend/grack_auth.rb

@@ -0,0 +1,54 @@
+module Grack
+  class Auth < Rack::Auth::Basic
+
+    def valid?
+      # Authentication with username and password
+      email, password = @auth.credentials
+      user = User.find_by_email(email)
+      return false unless user.try(:valid_password?, password)
+
+      # Set GL_USER env variable
+      ENV['GL_USER'] = email
+      # Pass Gitolite update hook
+      ENV['GL_BYPASS_UPDATE_HOOK'] = "true"
+
+      # Need this patch because the rails mount
+      @env['PATH_INFO'] = @env['REQUEST_PATH']
+
+      # Find project by PATH_INFO from env
+      if m = /^\/([\w-]+).git/.match(@env['PATH_INFO']).to_a
+        return false unless project = Project.find_by_path(m.last)
+      end
+
+      # Git upload and receive
+      if @env['REQUEST_METHOD'] == 'GET'
+        true
+      elsif @env['REQUEST_METHOD'] == 'POST'
+        if @env['REQUEST_URI'].end_with?('git-upload-pack')
+          return project.dev_access_for?(user)
+        elsif @env['REQUEST_URI'].end_with?('git-receive-pack')
+          if project.protected_branches.map(&:name).include?(current_ref)
+            project.master_access_for?(user)
+          else
+            project.dev_access_for?(user)
+          end
+        else
+          false
+        end
+      else
+        false
+      end
+    end# valid?
+
+    def current_ref
+      if @env["HTTP_CONTENT_ENCODING"] =~ /gzip/
+        input = Zlib::GzipReader.new(@request.body).read
+      else
+        input = @request.body.read
+      end
+      # Need to reset seek point
+      @request.body.rewind
+      /refs\/heads\/([\w-]+)/.match(input).to_a.first
+    end
+  end# Auth
+end# Grack