Amending three redirects as the destinations are themselves redirected

These are friendly URLs which resolve to PDF files. The PDFs in turn are redirceted to GOV.UK. No point hopping twice.
Adding new directgov PDF redirect

Asked for in Zen ticket #545970
Updating redirect URL to use http not https

The tests fail because of cutting & pasting https.
Merge pull request #587 from alphagov/adding_new_redirect_and_tidying

Adding new Directgov redirect and updating three others