Refactor daily visitors model to use recorder gem

Also move models into their own directory.
Refactor hourly visitors model to use recorder gem
Remove redundant gems from Gemfile
Refactor recorder to use recorder gem.
Move model update methods into models.

This is how the recorder class from the recorder gem
is expected to be used. Allso followed the style of the
method used in datainsight-insidegov-recorder/Policy.update_from_message
Rename FactoryGirl name for hourly to match model
Moved files around and renamed classes

Renamed model files to match classes
Moved recorder and renamed class to reflect there is only one.