Checking and Fixing URLs in the data

Our contact dataset contained a number of URLs about where the FOIA-centric webpage for that agency/department and the FOIA request form URL. 

Unfortunately a number of those webpages didn't work (returning 404 errors, or worse). 

This pull request contains a script to run the URL checker (we'll likely need to do this periodically). It also contains fixes for almost all the broken URLs. 
Yeah, it should actually. They no longer have an online request form. We don't have a method to 'delete' data manually, so I set it to empty string. If there's a better YAML way to do that, let me know.