Issue #2060691: Use Susy grid mixins

sass/partials/common/_user-profile.scss

@@ -52,9 +52,21 @@
 
   .aside {
     @include span-columns(3 omega);
+
     .da-membership-badge {
       @include span-columns(2, 3);
     }
+
+    // Grid of user pictures.
+    .field-name-field-mentors {
+      @include clearfix;
+      .field-item {
+        @include span-columns(1, 3);
+        @include nth-omega(3n);
+        margin-bottom: gutter(3);
+        line-height: 0;
+      }
+    }
   }
 }
 

sass/partials/drupalorg/_user-mentors.scss

-.page-user .field-name-field-mentors {
-  @include clearfix;
-
-  ul.links {
-    @include inline-block-list;
-  }
-
-  li {
-    line-height: 0;
-    margin: 0 5px 5px 0;
-  }
-
-  img {
-    height: auto;
-    max-width: 60px;
-  }
-}