Add search field to commits page

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/pages/commits.scss

@@ -28,10 +28,6 @@
   }
 }
 
-.commits-feed-holder {
-  float: right;
-}
-
 li.commit {
   list-style: none;
 

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

@@ -10,14 +10,20 @@
   .tree-ref-holder
     = render 'shared/ref_switcher', destination: 'commits'
 
-  .commits-feed-holder.hidden-xs.hidden-sm
+  .pull-right.hidden-xs.hidden-sm
     - if create_mr_button?(@repository.root_ref, @ref)
+      .pull-left.prepend-left-10
         = link_to create_mr_path(@repository.root_ref, @ref), class: 'btn btn-success' do
           = icon('plus')
           Create Merge Request
 
+    .pull-left.prepend-left-10
+      = form_tag(namespace_project_commits_path(@project.namespace, @project, @ref), method: :get, class: 'pull-left commits-search-form') do
+        = search_field_tag :search, params[:search], { placeholder: 'Filter by commit message', class: 'form-control search-text-input', spellcheck: false }
+
     - if current_user && current_user.private_token
-      = link_to namespace_project_commits_path(@project.namespace, @project, @ref, {format: :atom, private_token: current_user.private_token}), title: "Commits Feed", class: 'prepend-left-10 btn' do
+      .pull-left.prepend-left-10
+        = link_to namespace_project_commits_path(@project.namespace, @project, @ref, {format: :atom, private_token: current_user.private_token}), title: "Commits Feed", class: 'btn' do
           = icon("rss")