MAINTENANCE: Automated closing of pull requests.

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

Closes #3016 (close requested by 'andrewor14')
Closes #2798 (close requested by 'andrewor14')
Closes #2864 (close requested by 'andrewor14')
Closes #3154 (close requested by 'JoshRosen')
Closes #3156 (close requested by 'JoshRosen')
Closes #214 (close requested by 'kayousterhout')
Closes #2584 (close requested by 'andrewor14')