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

spec/observers/key_observer_spec.rb

@@ -0,0 +1,34 @@
+require 'spec_helper'
+
+describe KeyObserver do
+  before do 
+    @key = double('Key',
+      identifier: 'admin_654654',
+      key: '== a vaild ssh key',
+      projects: [],
+      is_deploy_key: false
+    )
+
+    @gitolite = double('Gitlab::Gitolite',
+      set_key: true,
+      remove_key: true
+    )
+
+    @observer = KeyObserver.instance
+    @observer.stub(:git_host => @gitolite)
+  end
+
+  context :after_save do
+    it do
+      @gitolite.should_receive(:set_key).with(@key.identifier, @key.key, @key.projects)
+      @observer.after_save(@key)
+    end
+  end
+
+  context :after_destroy do 
+    it do
+      @gitolite.should_receive(:remove_key).with(@key.identifier, @key.projects)
+      @observer.after_destroy(@key)
+    end
+  end
+end