Replace old logo

Author: leemunroe

README.md

@@ -1,5 +1,5 @@
 <p align="center">
-  <img src="https://onesignal.com/assets/common/logo_onesignal_color.png"/>
+  <img src="https://media.onesignal.com/cms/Website%20Layout/logo-red.svg"/>
 </p>
 
 ### OneSignal Flutter SDK [![Build Status](https://travis-ci.org/OneSignal/OneSignal-Flutter-SDK.svg?branch=master)](https://travis-ci.org/OneSignal/OneSignal-Flutter-SDK)
@@ -25,4 +25,4 @@ To make things easier, we have published a demo project in the `/example` folder
 
 #### Supports: 
 * Tested from iOS 8 to iOS 13
-* Tested from Android 4.0.3 (API level 15) to Android 9.0 (28)
+* Tested from Android 4.0.3 (API level 15) to Android 9.0 (28)