Implement checkConsistency API

[scottbelden]

This API was added recently and exists in the java script library. Any problems with adding it to the python one? If not, I don't mind taking a stab at it.

[scottbelden]

I started some work here as I wanted to use this functionality for something I'm playing with. I think the docstrings probably need some improvement and I haven't looked at the testing framework much to try to add tests, but from my manual testing it seems to work.

[todofixthis]

Hey @scottbelden that looks really good. Honestly, all it needs is some unit tests, and then I think it would be ready to merge!

As far as the docstrings go, I usually copy what's on https://iota.readme.io/v1.2.0/reference (although, that hasn't been updated with the new methods yet). Failing that, we could see if the JS lib has any info in their doc comments.

[scottbelden]

The PR has a commit with some tests (pretty much copy/pasted from get_latest_inclusion_test as they were pretty similar. The JS library just says returns whether the given tail is consistent

[todofixthis]

Oh. Well, that's... err, descriptive? 😸

I feel like we could make the description more helpful by including information about when an application might need to call checkConsistency, but I'm still trying to wrap my brain around the latest API changes myself — perhaps nobody knows 😆

[scottbelden]

I'm honestly not sure either... I just wanted to write a script that would reattach/promote all of my unconfirmed transactions and was basically just copying what the JS library did (without fully understanding exactly what the API does)

[plenarius]

I see from an older commit the comments about this method stated this, might be helpful

Should tell us if the subtangle below {tail} resolves to a consistent ledger

iotaledger-archive/iota.js@ec5ba38#diff-bb621303422b11c2aa40fb05b806c045L1937

So a proposal on comments:

# Used to ensure tail resolves to a consistent ledger which is necessary to validate before attempting promotion

[scottbelden]

Thanks. I included this as part of the updated docstring.

[todofixthis]

Scheduled for release: v2.0.3

Thanks @scottbelden !!