Fix Select value/selected React warning

Summary:
React outputs the following error:
  Warning: Use the `defaultValue` or `value` props on <select> instead of setting `selected` on <option>.

This fixes it by using value instead of selected.

Reviewed By: danielbuechele

Differential Revision: D15535717

fbshipit-source-id: eb784ba2cdefe1c6744cc15592cd3e0191d237d0

src/ui/components/Select.js

@@ -56,9 +56,10 @@ export default class Select extends Component<{
         grow={grow}
         id={this.selectID}
         onChange={this.onChange}
-        className={className}>
+        className={className}
+        value={selected || ''}>
         {Object.keys(options).map((key, index) => (
-          <option key={index} selected={key === selected}>
+          <option value={options[key]} key={index}>
             {options[key]}
           </option>
         ))}