Merge branch 'dropdown-caret-color' into 'master'

Fixes issue with dropdown caret being incorrect color

Previously:

![Screen_Shot_2016-03-16_at_19.31.20](/uploads/b887a7b8249f172513c68289c52a4cf7/Screen_Shot_2016-03-16_at_19.31.20.png)

Now:

![Screen_Shot_2016-03-16_at_19.29.37](/uploads/9c0d6a3002c18a8c7890df8dce612dcb/Screen_Shot_2016-03-16_at_19.29.37.png)



See merge request !3254

app/assets/stylesheets/framework/buttons.scss

@@ -139,7 +139,6 @@
 
   .caret {
     margin-left: 5px;
-    color: $gray-darkest;
   }
 }
 

app/assets/stylesheets/framework/dropdowns.scss

@@ -4,7 +4,7 @@
   height: 0;
   margin-left: 2px;
   vertical-align: middle;
-  border-top: $caret-width-base dashed $dropdown-caret-color;
+  border-top: $caret-width-base dashed;
   border-right: $caret-width-base solid transparent;
   border-left: $caret-width-base solid transparent;
 }

app/assets/stylesheets/framework/variables.scss

@@ -143,7 +143,6 @@ $dropdown-border-color: rgba(#000, .1);
 $dropdown-shadow-color: rgba(#000, .1);
 $dropdown-divider-color: rgba(#000, .1);
 $dropdown-header-color: #959494;
-$dropdown-caret-color: #54565b;
 $dropdown-title-btn-color: #bfbfbf;
 $dropdown-input-color: #c7c7c7;
 $dropdown-input-focus-border: rgb(58, 171, 240);