[BUILD] Fix PyPI, minor changes. (#2984)
[BUILD] Fix PyPI, minor changes. (#2984)

Fixes PyPI build and upload.
Adds option to build conda packages, upload them to S3 but without publishing them to anaconda.org.
Adds h2o.init to conda package check.
h2oai/h2o-3,h2oai/h2o-3,michalkurka/h2o-3,michalkurka/h2o-3,h2oai/h2o-3,michalkurka/h2o-3,michalkurka/h2o-3,h2oai/h2o-dev,michalkurka/h2o-3,h2oai/h2o-3,h2oai/h2o-dev,h2oai/h2o-3,h2oai/h2o-dev,h2oai/h2o-dev,michalkurka/h2o-3,michalkurka/h2o-3,h2oai/h2o-dev,h2oai/h2o-dev,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-dev