Update the color of the account drop-down menu

T-90

h/static/styles/top-bar.scss

@@ -62,3 +62,7 @@ $top-bar-height: 40px;
     color: $gray-dark;
   }
 }
+
+.top-bar__dropdown-arrow {
+  color: $color-dove-gray;
+}

h/templates/client/top_bar.html

@@ -63,7 +63,8 @@
         <a role="button"
            class="top-bar__btn"
            data-toggle="dropdown" dropdown-toggle>
-          <i class="h-icon-account"></i><i class="h-icon-arrow-drop-down"></i>
+          <i class="h-icon-account"></i><!-- nospace
+          !--><i class="h-icon-arrow-drop-down top-bar__dropdown-arrow"></i>
         </a>
         <ul class="dropdown-menu pull-right" role="menu">
           <li ng-show="authUser"><a href="/stream?q=user:{{account.username}}"