Signed-off-by: Alex Ellis <alexellis2@gmail.com>

- re-vendor queue-worker for publisher via 0.6.0
- bump queue-worker version to 0.6.0 in docker-compose.yml for
AMD64
- use new naming for NATS of nats -> NATS in variables where
required
- add default reconnect of 60 times, 2 seconds apart.

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

The basic-auth middleware and credentials-loading code has been
moved into the faas-provider project. This has now been brought
back into the faas project via vendoring.

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>