Add flvjs error handling, pass it to props onError method.

[mjankovskis]

When flvjs instance emits error it is not passed to the react player instance.

Expected behavior

Error should be passed to onError handler

Steps to Reproduce

git clone https://github.com/CookPete/react-player.git
cd react-player
npm install # or yarn
npm start
open http://localhost:3000

In Custom URL write file.flv

> events.js:62 Uncaught (in promise) Error: Uncaught, unspecified "error" event. (NetworkError)
    at i.emit (events.js:62:1)
    at i.<anonymous> (flv-player.js:236:27)
    at i.emit (events.js:84:1)
    at transmuxer.js:189:27

After fix

> onError NetworkError

[cookpete]

Published in 2.10.1