Remove yarn, just adds complexity

[bhouston]

Describe the feature you'd like:

I would propose we remove yarn. NPM is faster and more reliable than it was years ago. Yarn just adds an unnecessary dependency and a global install. Also there are multiple versions of yarn and it can be confusing as to which to you as they are not compatible with each other.

Suggested implementation:

I have a branch that removes yarn and everything appears to work.