lisa.datautils: Remove support for pandas < 1.0.0
lisa.datautils: Remove support for pandas < 1.0.0

Since we mandate higher version in setup.py, there is no need to support
earlier versions anymore.

ARM-software/lisa,ARM-software/lisa,ARM-software/lisa,ARM-software/lisa,credp/lisa,credp/lisa,credp/lisa,credp/lisa