Fix 16 linter warnings in Examples/

Summary: Partially fixes #3316 by addressing 16 linter warnings:
 - Strings should be singlequote
 - Missing semicolon

Travis build jobs 1.1 through 1.4 complete successfully. 1.5 fails through what appears to be an unrelated issue on master.
Closes https://github.com/facebook/react-native/pull/3332

Reviewed By: @​svcscm

Differential Revision: D2531718

Pulled By: @javache

fb-gh-sync-id: ca22fbeac5fe3b4f725775a72f21b6dd7a75d94b

Libraries/ReactIOS/WarningBox.js

@@ -135,12 +135,12 @@ var WarningRow = React.createClass({
     });
     this.panGesture = PanResponder.create({
       onStartShouldSetPanResponder: () => {
-        return !! this.dismissalSpring.getCurrentValue();
+        return !!this.dismissalSpring.getCurrentValue();
       },
       onMoveShouldSetPanResponder: () => true,
       onPanResponderGrant: () => {
         this.isResponderOnlyToBlockTouches =
-          !! this.dismissalSpring.getCurrentValue();
+          !!this.dismissalSpring.getCurrentValue();
       },
       onPanResponderMove: (e, gestureState) => {
         if (this.isResponderOnlyToBlockTouches) {