Ripple hashes integration

[Stormtv]

According to #960 there was a need to remove the ripple hashes dependency and locally include it in this project.

I went through and copied the functionality of ripple hashes and rewrote the library in Typescript and implemented it and the unit tests associated with it.

Let me know if you have any questions or feedback.

Thanks!

[Stormtv]

One thing I removed from the ripple hashes lib was a dependency of https://github.com/crypto-browserify/createHash since this package only loads the createHash function from the node crypto package. I assume the existing webpack should browserify this without this package.

[keefertaylor]

With regards to the number / string change, I think your change looks reasonable. You might consider adding some tests to make sure that you have reasonable behavior when someone passes you 42.

I have mixed feelings on whether this made the code more readable. I do think it's slightly easier to assert that a number is 0-15 than a string is "0"-"F", so I think that's a win.

[keefertaylor]

Ship it!

[Stormtv]

Alright I think I've finished all the review changes lmk if there is anything else. If not this is good to go.

[sublimator]

Lol, seriously!??

[keefertaylor]

@sublimator Can you clarify what you think is still missing here?

[sublimator]

Haha - :)

[sublimator]

Just trolling :) TBH I haven’t paid proper attention :/

[Stormtv]

@sublimator No rush on this. If you need more time to review it we can wait to merge this until your approval.

[sublimator]

Lol :)

[sublimator]

Sorry guys, old man blues :)

[intelliot]

Looks good to me, big thanks to all of you for the work and reviews! I went ahead and squashed this PR with the merge, hope that's OK. Let me know if anyone experiences any issues.