Show preview panel when showPreview is false but showSkinTones is true.

This is necessary in order to be able to show skin tone picker even when
one desires for the mouseover preview to be invisible. This is an
important case because mouseover displays must be disabled in order to
enable single click emoji typing on iOS without disabling the skin tone
picker.

src/components/picker/nimble-picker.js

@@ -560,7 +560,7 @@ export default class NimblePicker extends React.PureComponent {
           })}
         </div>
 
-        {showPreview && (
+        {(showPreview || showSkinTones) && (
           <div className="emoji-mart-bar">
             <Preview
               ref={this.setPreviewRef}
@@ -568,6 +568,7 @@ export default class NimblePicker extends React.PureComponent {
               title={title}
               emoji={emoji}
               showSkinTones={showSkinTones}
+              showPreview={showPreview}
               emojiProps={{
                 native: native,
                 size: 38,

src/components/preview.js

@@ -23,9 +23,10 @@ export default class Preview extends React.PureComponent {
         title,
         emoji: idleEmoji,
         i18n,
+        showPreview,
       } = this.props
 
-    if (emoji) {
+    if (emoji && showPreview) {
       var emojiData = getData(emoji, null, null, this.data),
         { emoticons = [] } = emojiData,
         knownEmoticons = [],