docker-compose: introduce fake hosts in docker.mender.io domain
docker-compose: introduce fake hosts in docker.mender.io domain

Instead of single-label hostnames that may pose problems with picky
resolvers, introduce legitimate DNS names. The following names are
aliased in compose:

- API gateway:
  - docker.mender.io
- fakes3
  - s3.docker.mender.io
  - mender-artifact-storage.s3.docker.mender.io

When using locally, one may need to map these names to 127.0.0.1 in
/etc/hosts.

Signed-off-by: Maciej Borzecki <f609d9f713abcd5f8f0e51f08dc151638a7681e7@rndity.com>

GregorioDiStefano/integration,GregorioDiStefano/integration,pasinskim/integration,pasinskim/integration,pasinskim/integration