Can not install Ludwig due the error:
ERROR: Could not find a version that satisfies the requirement tensorflow==1.15 (from versions: 2.2.0rc1, 2.2.0rc2, 2.2.0rc3, 2.2.0rc4, 2.2.0, 2.3.0rc0, 2.3.0rc1)
ERROR: No matching distribution found for tensorflow==1.15
pip is updated (pip 20.1.1) but doesn't have tensorflow==1.15.3 anymore