Find and remove any dead/unused Python code.

Determine whether or not it's worth running Vulture as a pre-commit hook, or if it should be something we do periodically instead.

• Run Vulture. Investigate any findings and remove any dead code. (0d) - @shreyamalviya
• Add a pre-commit hook to run vulture. (0d) @mssalvatore
• Fail travis build if vulture finds dead code. (0d) @mssalvatore
• Run blackbox tests (0.25d) @mssalvatore