Check if 2FA is required and trigger SMS if needed

[jeppenejsum]

Currently, SMS seems not to be supported for 2FA.

This PR checks for 2FA and only asks for code if required. This also triggers an SMS if 2FA is configured to use this. Uses same solution as in mislav/hub#435

[linuxus]

2FA still fails on my git push command... I don't have SMS but using Google Authenticator iPhone App. 2-factor Authentication works on the web portal but I don't get any prompt on the command shell:
git push origin master
fatal: Authentication failed

[jeppenejsum]

@linuxus Not sure how this is related to this repo (or this PR)

[rvagg]

@jeppenejsum could you talk me through this as someone who doesn't use SMS 2FA? Does the mere fact of doing a POST trigger an SMS to be sent?

[rvagg]

fwiw I'm happy with this, I just need to understand how it works

[jeppenejsum]

@rvagg Yes doing a POST triggers the SMS and that's how it's done in the hub application. See this commit for some details: mislav/hub@e70f7ba

[rvagg]

released as 0.2.0, added you as a collaborator @jeppenejsum so you can take responsibility for any bug reports from this!