Update React Native documentation (0.49)

Author: Thibaut

lib/docs/scrapers/react_native.rb

@@ -3,7 +3,7 @@ class ReactNative < React
     self.name = 'React Native'
     self.slug = 'react_native'
     self.type = 'react'
-    self.release = '0.48'
+    self.release = '0.49'
     self.base_url = 'https://facebook.github.io/react-native/docs/'
     self.root_path = 'getting-started.html'
     self.links = {