mongodb interface is outdated

[AdamIsrael]

The mongodb interface, provided by cloud-green, is deprecated and may not be functional anymore. It should be checked and, if not functional, removed from the index, and preferably replaced by a functional version.

[AdamIsrael]

@johnsca I believe we checked, a few months back, and confirmed that there were no recent pulls of the interface. I have a replacement interface I'd like to propose, but want to confirm that's still the case.

@cmars You're the last committer to the current version. Last we spoke, the interface wasn't being maintained (the last commit was two years ago). Do you have any objection to it being replaced with a new version?

[cmars]

No objections here!