suggestion: add 2FA

[balaenacaridea]

Hi, I suggest to add 2FA functionality, from Google authenticator, to upgrade the security of the wallet. Would very much appreciate if you did

kind regards, amf

[ShieldCoin]

We were already going to do that but I'll keep updates in here

[ShieldCoin]

We'll use this I guess: https://davidwalsh.name/2fa