Improve font size on issues/mr list

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

app/assets/stylesheets/pages/issues.scss

 .issues-list {
   .issue {
-    padding: 10px 15px;
+    padding: 10px $gl-padding;
     position: relative;
 
     .issue-title {
@@ -11,7 +11,6 @@
 
     .issue-info {
       color: $gl-gray;
-      font-size: 13px;
     }
 
     .issue-check {

app/assets/stylesheets/pages/merge_requests.scss

@@ -128,7 +128,6 @@
 
     .merge-request-info {
       color: $gl-gray;
-      font-size: 13px;
     }
 
   }

app/views/projects/issues/_issue.html.haml

@@ -41,4 +41,4 @@
         = issue.task_status
 
     .pull-right.issue-updated-at
-      %small updated #{time_ago_with_tooltip(issue.updated_at, placement: 'bottom', html_class: 'issue_update_ago')}
+      %span updated #{time_ago_with_tooltip(issue.updated_at, placement: 'bottom', html_class: 'issue_update_ago')}

app/views/projects/merge_requests/_merge_request.html.haml

@@ -43,4 +43,4 @@
         = merge_request.task_status
 
     .pull-right.hidden-xs
-      %small updated #{time_ago_with_tooltip(merge_request.updated_at, placement: 'bottom', html_class: 'merge_request_updated_ago')}
+      %span updated #{time_ago_with_tooltip(merge_request.updated_at, placement: 'bottom', html_class: 'merge_request_updated_ago')}