Improve html dumps

Previously if multiple threads failed they would override each others
dumps.
Add some notes about logging to the README
Make textbook scrape use logging
Forgot to import
Fix, write as binary
Fixed: duplicated logging statements

Logger was used before being setup. Logger setup moved before relevant
logging statements, and placed within `__name__ == "__main__"` block to
prevent the logger from being setup twice when main.py used as a
library.
Fix duplicated logging statements in a better way
Merge pull request #15 from Queens-Hacks/logging

Logging Improvements
Merge branch master into retry-requests