Remove journey since it was merged into Rails, and change deprecated rubygems source
Revert "Merge pull request #43 from rubys/rails_issues_9461"

This reverts commit ccf92ee40cb4c9a966a22106a721f7364b5fc6c9, reversing
changes made to 8105eb9ee2d4889f9d3d7c327899b63493f4b061.

Reason: Helper module should be included into AV::Base, extending it with
the helpers and config options.