Drop RC tag

[boyuanzz]

We are going to drop RC tag in order to make it installable trough pypi
r: @pabloem
cc: @charlesccychen

[pabloem]

LGTM
For posterity, we do this to simplify the release process. It can be reverted later if necessary.

[charlesccychen]

Thanks Boyuan! For more context, this fixes an issue where pip install of wheel packages didn't work because of the RC tag which was present upon uploading to PyPI.