Add scripts for Metroextractor

[migurski]

Thinking about where it might be appropriate to add scripts for performing various Extracts tasks, I came up with this. It’s got a chef recipe that installs the package via setup.py based on relative directory paths (is this safe?) and one script so far that does nothing but write a file, e.g.:

extracts-nothingburger -122.3073 37.8005 -122.2407 37.8331 /tmp/output.txt

I’d like to add the remainder, and support them.

• Show that Python scripts can be added in this way.
• Add WoF download script.
• Add OpenAddresses download script.
• Add Vector Tile download script from @iandees.

The plan that @sleepylemur and I discussed for this is that we’d dark launch these features first to be sure that they work, then support them for the core 200 cities, and later add support in on-demand extracts.