RNTester enhancement for Slider (#45)

* RNTester: Support `platforms` array on examples
* RNTester: enable Slider thumbTintColor on DOM

Author: motiz88

js/RNTesterExampleContainer.js

@@ -18,12 +18,17 @@ const RNTesterPage = require('./RNTesterPage');
 class RNTesterExampleContainer extends React.Component {
   renderExample(example, i) {
     // Filter platform-specific examples
-    var {title, description, platform} = example;
+    var {title, description, platform, platforms} = example;
     if (platform) {
       if (Platform.OS !== platform) {
         return null;
       }
       title += ' (' + platform + ' only)';
+    } else if (platforms) {
+      if (platforms.indexOf(Platform.OS) === -1) {
+        return null;
+      }
+      title += ' (' + platforms.join("/") + ' only)';
     }
     return (
       <RNTesterBlock

js/SliderExample.js

@@ -131,7 +131,7 @@ exports.examples = [
   },
   {
     title: 'Custom thumb color',
-    platform: 'android',
+    platforms: ['android', 'dom'],
     render(): React.Element<any> {
       return <SliderExample thumbTintColor={'blue'} />;
     }