Add Endpoint.update(id,data) method

[jamesharr]

Adds an Endpoint.update(id,data) call to the endpoint API.

Closes #125

[jvanderaa]

I like the plan here. Any chance you would like to take a crack at a test on it? Otherwise I may be able to get that test written in a couple of days here (scheduling, not time to do to the test).

[jamesharr]

@jvanderaa

I took a stab at tests and docs. I'm more confident in the testing than the docs 😆

[jamesharr]

Sorry about the weird commit list; I rebased against main, then rebased against develop