Revisions sometimes start at 2 - work around this

This is an intermediate fix. There's a user record that never had it's database created. The first time it shows up in the changes feed the revision starts with 2-. Not sure why this is. But we loose this user record if we rely on CouchRest::Changes.created which checks for a revision starting with 1-.
Merge pull request #8 from azul/bugfix/fix-for-revisions-starting-above-1

Revisions sometimes start at 2 - work around this
fix UserDatabase#prepare
properly refer to logger in user_database
Merge branch 'master' of github.com:leapcode/tapicero into test/integration-with-travis