MAINTENANCE: Automated closing of pull requests.

This commit exists to close the following pull requests on Github:

Closes #3456 (close requested by 'pwendell')
Closes #1602 (close requested by 'tdas')
Closes #2633 (close requested by 'tdas')
Closes #2059 (close requested by 'JoshRosen')
Closes #2348 (close requested by 'tdas')
Closes #3662 (close requested by 'tdas')
Closes #2031 (close requested by 'andrewor14')
Closes #265 (close requested by 'JoshRosen')

Author: pwendell