[RELEASE]: v0.9.9

[humzaiqbal]

Description of proposed changes

Stamping a new release v0.9.9 for this issue https://github.com/snorkel-team/snorkel/pull/1690

Related issue(s)

Fixes # (issue)

Test plan

Existing tests should cover it

Checklist

Need help on these? Just ask!

• [ ] I have read the CONTRIBUTING document.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] I have run tox -e complex and/or tox -e spark if appropriate.
• [ ] All new and existing tests passed.

[rjurney]

Excited to see this happening!

[rjurney]

Scikit learn is really old in requirements.txt, which makes the package a little obsolete in terms of running it. Is this something that could go on this release?