Prefer snake_case to camelCase

Because it's Ruby style.
Remove HTTPS from VirtualBox download URL

This hostname has stopped responding to TLS requests.
Merge pull request #687 from alphagov/vagrantfile-improvements

Vagrantfile improvements
Tidy up remove lumberjack

This just removed what we added in in the recent switch to
logstashforwarder. It seems there are a few other resources related to
lumberjack still lying around.
Merge pull request #688 from alphagov/tidy-up-remove-lumberjack

Tidy up remove lumberjack