Use POST for key deletion

[ashokdelphia]

(Note that this builds on top of the change for #9, so the intended change here is just the second commit.)

• Use a POST request for deleting keys. (077a9e2)

  Side-effecting on GET is somewhat hazardous.

[ashokdelphia]

I'll re-make this once I have the tests running locally.

[mkalioby]

Sure

I'll write a document about running tests soon.

Thanks for the help.