Added in SSL Certificate Pinning using RNPinnedCertValidator library

[hongkongkiwi]

I've added SSL certificate pinning into the library, it relies on a new submodule RNPinnedCertValidator.

What is SSL pinning? It essentially adds an extra layer of security by checking a chain of trust against a local set of public certificate files (the files are stored in the bundle). This is useful to prevent Man in the middle attacks.

Here are some steps for setting up pinning in AFNetworking. The steps are the same to produce the cer file.

Once you have a .cer file, simply put it in your bundle and setup the library like this before connect

self.socketIO.useSSLPinning = YES;
self.socketIO.sslPinningCert = @"ca-file"; // Without the .cer extension

That's it!