NetInfo deprecated warnings

[jakejackson1]

Just testing out this package and noticed a few deprecated warnings:

NetInfo.fetch() is deprecated. Use NetInfo.getConnectionInfo() instead
NetInfo's "change" event is deprecated. Listen to the "connectionChange" event instead

[sorodrigo]

Thanks! I'm aware of this changes. Will update them asap.

[kbrandwijk]

As I read in redux-offline#49 that a new release might be imminent, I submitted a PR to get rid of those pesky warnings.

[sorodrigo]

Thanks! 😄