Update finance.yml

Add xero
Added in xero logo
Added mailgun (mailgun.com)
Mailgun twitter handle added
Merge pull request #433 from edwardabraham/master

Add Xero and Mailgun
Added StatusCake to Developer (has 2FA)

StatusCake.com is a website uptime monitoring tool.
Added Zapier to Developer (no 2FA)

Zapier is an API/platform automation tool.
Added MyDomain.com to Domains
add UWCU to finance

UWCU HMAC-OTP, phone and SMS confirmed
added UWCU image
fixed image for UWCU
really fixed UWCU image this time
Merge pull request #437 from curieux/master

Added UWCU (University of Wisconsin Credit Union)
social: add FR Viadeo
social: add Viadeo image + twitter
backup: add synology + image
image 32x32
image 32x32
Changed Authy's methods

If I'm not mistaken, Authy can text you, call you (for some sites like Coinbase), use software, and give you hardware tokens (for some sites).
Oops accidentally put an example in there!