BLD: bump xlrd min version to 1.2.0
Warnings about time.clock are filling up the py37 min_version build.  xlrd 1.2.0 was released Dec 15, 2018, so I think we're safe to bump it.
not sure if there is an open issue about this? > not sure if there is an open issue about this?

doesn't look like it. `ignore_xlrd_time_clock_warning` added in #23727 see also https://github.com/pandas-dev/pandas/pull/23727#discussion_r235957934

