change pandas version up one.

Also change the setup.py versions to the minimum numpy and pandas
versions tested by travis.
Fixed logical flow for missing Crotate extension
Remove requests.
Remove ref to requests in ref.
Fix tests.
Merge pull request #814 from ayshih/Crotate

Fixed logical flow for missing Crotate extension
Doc update.
Merge pull request #817 from segfaulthunter/pytestblah

Fix download tests.
Merge pull request #815 from segfaulthunter/requests

Remove requests.
Merge pull request #790 from Cadair/pandas_version_update

change pandas version up one.