Implement review comments from @axil.

1. Align "Allowed to Merge" and "Allowed to Push" dropdowns.

2. Don't display a flash every time a protected branch is updated.
   Previously, we were using this so the test has something to hook onto
   before the assertion. Now we're using `wait_for_ajax` instead.

app/views/projects/protected_branches/index.html.haml

@@ -32,7 +32,6 @@
             are supported.
 
         .form-group
-          .prepend-left-10
           = f.hidden_field :allowed_to_merge
           = f.label :allowed_to_merge, "Allowed to merge: ", class: "label-light append-bottom-0"
           = dropdown_tag("<Make a selection>",
@@ -41,7 +40,6 @@
                                     data: { field_name: "protected_branch[allowed_to_merge]" }})
 
         .form-group
-          .prepend-left-10
           = f.hidden_field :allowed_to_push
           = f.label :allowed_to_push, "Allowed to push: ", class: "label-light append-bottom-0"
           = dropdown_tag("<Make a selection>",

spec/features/protected_branches_spec.rb

 require 'spec_helper'
 
 feature 'Projected Branches', feature: true, js: true do
+  include WaitForAjax
+
   let(:user) { create(:user, :admin) }
   let(:project) { create(:project) }
 
@@ -109,7 +111,7 @@ feature 'Projected Branches', feature: true, js: true do
           within('.dropdown-menu.push') { click_on access_type_name }
         end
 
-        expect(page).to have_content "Updated protected branch"
+        wait_for_ajax
         expect(ProtectedBranch.last.allowed_to_push).to eq(access_type_id)
       end
     end
@@ -140,7 +142,7 @@ feature 'Projected Branches', feature: true, js: true do
           within('.dropdown-menu.merge') { click_on access_type_name }
         end
 
-        expect(page).to have_content "Updated protected branch"
+        wait_for_ajax
         expect(ProtectedBranch.last.allowed_to_merge).to eq(access_type_id)
       end
     end