Add new deployment task type

for updates to Fastly config files.
Create sbt-debug to help debugging in IDE
Add checking to each stage of fastly task
Separate out credentials
Fetch credentials from property file temporarily
Modify credential implementation

So that there is now a generic ApiCredential to hold service, ID and secret.
Merge remote-tracking branch 'origin/master' into kc-fastly

Conflicts:
	riff-raff/app/deployment/deployinfo.scala
Decouple creation of Fastly API client

So that task can be tested without making calls on Fastly API.
Add tests
[#47708307] Enable uploading new vcl files

Previously, files could only be updated if an earlier version had already been uploaded.
Merge branch 'master' into kc-fastly

Conflicts:
	magenta-lib/build.sbt
Fix dis-agreement over scala version (2.10 vs 2.10.0)
Now referencing the fastly api client hosted on guardian github release
For comprehension asked for by Phil
Merge branch 'master' into kc-fastly
Merged master, with some conflicts
Now using a newer version of the FastlyAPIClient
UpdateFastlyConfig class - moved the inner methods out of the execute() method to make it easier to read
Removed fastly.vcl
Removed a newline so that it disappears from the diff