Archive controller

- Queries DynamoDB to look for redirect matches (and sends a http 301 if found).
- Queries S3 to look for archive pages (and sends the archived file contents along with an http 200)

The former currently houses 1.5m R1 redirects, and the S3 bucket houses a few hundred thousand R1 files taken off the docroot.

If it doesn't find anything then it serves a 404.

Eg,

 - http://localhost:9000/404/www.theguardian.com/media/emailservices/article/0,,1694396,.html - found in dynamo (http 301)
 - http://localhost:9000/404/travel.theguardian.com/askatraveller/0,,345059,00.html - archived in s3 (http 200)
 - http://localhost:9000/404/www.theguardian.com/i/am/not/here.html - not found (http 404)

Misc.

- @gklopper I'm introducing this in to Applications while I test this whole idea, but we split it off to a dedicated stack (later?).
- Lacks tests.
Send a proper 404
Protect against more than one record being returned
Minor fixes from PR
Split archive in to a self-container application

- Added tests
- Moved S3Archive object to services.S3
Fix failing test
Add mgmt URLs & healthcheck to archive server
Move context.scala to the correct location
Fix management stuff
Merge branch 'r1-redirects' of github.com:guardian/frontend into r1-redirects
Merge pull request #3150 from guardian/r1-redirects

R1 redirects