PDF generation - spike

The idea is to have this generate a PDF
synchronously for demo purposes only.
The code will be ripped out later &
added to a standalone app.
Added Sidekiq

One spec for PDFMaker is broken.
Needs to be re-thought and done 'properly'.
Another failing test that needs to be re-thougth
Implemented PDF form filling from JSON

Uses the YAML file with the values to do the mapping
Added Redis start up to TravisCI config
Added redis as a TravisCI service

Removed the previous setup for Redis
Merge pull request #56 from ministryofjustice/pdf-form-filling

PDF form filling