try catch for writeStagedState serialize

[SethArchambault]

Even though there was ".catch" on this line, it only caught errors from setItem, so an error from serialize would be completely unhandled.

This will at least give a more helpful error message than this raw error:

RangeError: Out of memory
  at stringify([native code])
  at writeStagedState(node_modules/redux-persist/lib/createPersistoid.js:90:48)
  at processNextKey(node_modules/redux-persist/lib/createPersistoid.js:78:7)
  at _callTimer(node_modules/react-native/Libraries/Core/Timers/JSTimers.js:130:7)
  at apply(node_modules/react-native/Libraries/Core/Timers/JSTimers.js:383:7)
  at __callFunction(node_modules/react-native/Libraries/BatchedBridge/MessageQueue.js:416:27)
  at fn(node_modules/react-native/Libraries/BatchedBridge/MessageQueue.js:109:12)
  at __guard(node_modules/react-native/Libraries/BatchedBridge/MessageQueue.js:364:9)
  at value(node_modules/react-native/Libraries/BatchedBridge/MessageQueue.js:108:10)
  at value([native code])

[SethArchambault]

Note that this needs some testing..