fix selenium closed browser too early by putting wait back in

this means you can't automate the script anymore, but I wasn't doing
that anyways.
delete unnecessary logging code from csv reader
doc next steps for firefox driver
make the script fail faster if you don't have your environment set up
fix browsers don't know how to interpret relative_paths for mvl files
Merge pull request #2 from texastribune/tweaks

minor tweaks