Update README.md

Update React native version to 3.2.0.

Author: simoarpe

README.md

@@ -111,7 +111,7 @@ PSPDFKit.present('document.pdf', {
 - Android SDK
 - Android Build Tools 23.0.1 (React Native)
 - Android Build Tools 25.0.2 (PSPDFKit module)
-- PSPDFKit >= 3.0.0
+- PSPDFKit >= 3.2.0
 - react-native >= 0.45.1
 
 #### Getting Started