Make Visit project on GitLab button goes to The internal Gitlab project

Since we are merging CI into CE, projects should go to the internal Projects
page, we can also use Turbolinks to do so.

In order to give the user an idea of integration, I renamed the button: "Go to
Project"

Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>

app/views/ci/projects/show.html.haml

@@ -17,7 +17,7 @@
       = link_to @ref, ci_project_path(@project, ref: @ref)
   %li.pull-right
-    = link_to 'View on GitLab', @project.gitlab_url, no_turbolink.merge( class: 'btn btn-sm' )
+    = link_to 'Go to project', project_path(gl_project), class: 'btn btn-sm'
 - if @ref
   %p