cargo-verify output options: json, ascii, etc. ?

[alastairreid]

Output is only suitable for human consumption at the moment.
It would be nice to be able to connect it to other tools so that we can do things like:

• aggregate the result of verifying multiple programs/libraries
• collect data about the trajectory of passing checks through time

(A likely side-effect is that using 'cargo-verify -j' could probably produce output in a less disorganized manner?)

I think that the code that cargo-test uses is here.