Logging

Closes #59. I'm unsure how to actually get to some of the messages to test whether certain parts log correctly. It does correctly log uncaught exceptions and HTTP requests though.
The location of the log files (both `'log/app.log'` and `'log/werkzeug.log'`) and perhaps the maxbytes too, yeah.  The format string is fine there, but maybe declare it as it's own variable so it's clear what it is.