remove redundant nibble traversal for extensions when verifying a proof

[thecodingshrimp]

Problem

The verify function of the MerklePatriciaProof.sol smart contract does not process extensions correctly.

Problem Specifics

In lines 62-65 it checks if there is an extension at pathPtr. But, since pathPtr was already incremented in line 53, it can never detect an extension.

Solution

Remove lines 62-65 since we just traverse an extension and want to check for the next nibble.

[thecodingshrimp]

@sammayo @zmitton let me know what you think!

[zmitton]

Cool. It looks like we did write tests. Were you able to get them to run? If so, could you create a test case that currently fails on an extension and succeeds with the changes?

[thecodingshrimp]

Cool. It looks like we did write tests. Were you able to get them to run? If so, could you create a test case that currently fails on an extension and succeeds with the changes?

I only used this one contract from your repo, so will try to get them to run. An initial try failed since a lot of packages are outdated now and don't run with a recent node version.

Will update the packages and get it to run and then write a test case. The ladder isn't too complicated as I have already written one for my project.

I am in a region with bad internet right now. Will work on it in the middle of march!

[thecodingshrimp]

Build a small test suite and found a bug in the RLP smart contract which needs to be fixed as well. Some packages also need to be updated.

Should I create a separate PR for the RLP bug and the updating of the packages or can I do everything in one?