Fix project page with activity as default home page

app/assets/stylesheets/pages/projects.scss

@@ -331,3 +331,9 @@ pre.light-well {
   padding: 10px 15px;
   margin: 0;
 }
+
+.project-show-activity {
+  .activity-filter-block {
+    margin-top: -1px;
+  }
+}

app/views/projects/_activity.html.haml

 = render 'projects/last_push'
-.gray-content-block
+.gray-content-block.activity-filter-block
   - if current_user
     %ul.nav.nav-pills.event_filter.pull-right
       %li

app/views/projects/show.html.haml

@@ -65,8 +65,10 @@
 
 %section
   - if prefer_readme?
+    .project-show-readme
       = render 'projects/readme'
   - else
+    .project-show-activity
       = render 'projects/activity'