Commits
Wes McKinney authored ba4f478e7c6
ARROW-715: [Python] Make pandas not a hard requirement, flake8 fixes Author: Wes McKinney <wes.mckinney@twosigma.com> Closes #462 from wesm/ARROW-715 and squashes the following commits: 21fe8eb [Wes McKinney] Make pandas not a hard requirement, flake8 fixes