fix(Textarea): Abstract border on firefox

packages/component-faraday-ui/src/Textarea.js

@@ -17,6 +17,8 @@ const Textarea = styled.textarea`
   padding: ${th('gridUnit')};
   width: 100%;
   resize: vertical;
+  border-style: ${th('borderStyle')};
+  border-width: ${th('borderWidth')};
 
   ${minHeight};
   ${marginHelper};