publish a preliminary version of udiff to PyPI

[sangyx]

We have implemented the basic functions. I think it's time to publish a preliminary version of udiff to PyPI. But I don't have the account. Could you publish it?

[hameerabbasi]

udiff isn't published on PyPI so far, so you should be able to publish this package fairly easily. I think it's about time we recognized your role in this project -- I'll add you to the collaborators. In addition, unumpy and uarray will need releases, I'll manage those.

[sangyx]

Hi, I encountered an error Invalid value for requires_dist. Error: Can't have direct dependency: 'uarray @ git+https://github.com/Quansight-Labs/uarray@master#egg=uarray' when I try to upload udiff to pypi. It seems that pypi does not allow direct URLs as the issue #6301 mentioned.

[hameerabbasi]

Yes, unumpy and udiff need releases, and we'll then need a PR to (temporarily) change the deps to point at the released versions, tag it, then release.