arrow

ARROW-5294: [Python] [CI] Fix manylinux1 build

There is a regression in setuptools_scm 3.3.0:
https://github.com/pypa/setuptools_scm/issues/333

Author: Antoine Pitrou <antoine@python.org>

Closes #4276 from pitrou/fix-manylinux-build and squashes the following commits:

c17ec3e97 <Antoine Pitrou>   Fix manylinux1 build