Switching to latest version of backdrop-collector

The latest version of backdrop-collector has an extra parameter in set_up_logging() which allows one to specify the logfile_path. Previously logfiles were being created in a place relative to cron's working directory.
Merge pull request #15 from alphagov/update-logging

Switching to latest version of backdrop-collector
Break up line so pep8 passes
Merge pull request #17 from alphagov/pep8-fix

Break up line so pep8 passes