[FYI] Simula card is removed from gke.mybinder.org, 2i2c card is now our primary card

[choldgraf]

Context

@minrk got Simula to agree to paying for two months of gke.mybinder.org's credits while we were under a credit crunch. Those two months are now up. Fortunately we have some credits from Google on the way (#463) but we still need to define a credit card that will be used in case those credits run out.

For now, I have added the 2i2c Expensify card to pay for gke.mybinder.org in case this happens. Longer-term, I think it would be better if Jupyter provided its own financial mechanism for payment that could act as a backstop. But this is a stop-gap until that happens.

[choldgraf]

Going to close this one - just wanted to let y'all know!