Merge branch 'display-message-when-assignee-cannot-merge' into 'master'

adds exclamation point when assigned user cannot merge

Fixes: #4175 

See merge request !2408

app/assets/stylesheets/framework/variables.scss

@@ -26,6 +26,7 @@ $gl-vert-padding: 6px;
 $gl-padding-top:10px;
 $gl-avatar-size: 46px;
 $secondary-text: #7f8fa4;
+$error-exclamation-point: #E62958;
 
 /*
  * Color schema

app/assets/stylesheets/pages/projects.scss

@@ -558,3 +558,9 @@ pre.light-well {
     width: 101%;
   }
 }
+
+.cannot-be-merged, 
+.cannot-be-merged:hover {
+  color: #E62958;
+  margin-top: 2px;
+}

app/views/shared/issuable/_sidebar.html.haml

@@ -10,6 +10,9 @@
       .value
         - if issuable.assignee
           %strong= link_to_member(@project, issuable.assignee, size: 24)
+          - if issuable.instance_of?(MergeRequest) && !issuable.can_be_merged_by?(issuable.assignee)
+            %a.pull-right.cannot-be-merged{href: '#', data: {toggle: 'tooltip'}, title: 'Not allowed to merge'}
+              = icon('exclamation-triangle')
         - else
           .light None