Setup MM2 playground node.

[artemii235]

A public node that will be available to play with using Postman collection from KomodoPlatform/developer-docs#362
Notes from Discord

• Node should be redeployed automatically on CI builds for dev branch.
• Node should be supplied with a bit of RICK/MORTY and other test coins.
• In the future, if this playground is used alot, to avoid the quick depletion of the test coins we can limit the amount that can be put on each order for this node, this can be done by adding an argument to the mm2 command.
• we can do some rate limits depending on incoming IP Address

[onur-ozkan]

done

ref #1280