[nocheck] Add python 3.7 to prerequisites (#5879)
[nocheck] Add python 3.7 to prerequisites (#5879)

* Add python 3.7 to prerequisites

* Change prerequisites to "3.5x to 3.7.x"
h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3,h2oai/h2o-3