Fix bug introduced by URL transformer

This prevented Prometheus metrics from being gathered from the
URL.

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

Bump up the gateway to 0.8.11

I am moving gateway build version to 0.8.11

Signed-off-by: Martin Dekov (VMware) <mdekov@vmware.com>

Attach X-Call-Id to asynchronous calls

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

Adds HTTP Host entry

Fixes: openfaas/of-watchdog#24

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

Expose scale-function endpoint

- exposes scale-function endpoint for use with faas-idler, this
is protected by auth when enabled.

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

Bump gateway version to 0.8.7

This commit bumps gateway version to 0.8.7 in docker-compose.yml and
also adds `scale_from_zero` environment variable to the gateway.

Fixes: openfaas#780

Signed-off-by: Vivek Singh <vivekkmr45@yahoo.in>

Refactor scaling to use existing code

Existing code has been used for scaling up and querying replicas.
This meant the new code was deleted and there is less duplication
now.

The cache store a whole query response rather than just the
available replica count and the tests were updated. This has been
tested with Docker swarm and the image:
 openfaas/gateway:scale-17-07-2018

This feature now needs the env-var of scale_from_zero to be enabled
in order to turn on the scaling behaviour.

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

Move CI to use openfaas/* ns

This was a miss by refactoring work and is causing a CI failure

https://travis-ci.org/openfaas/faas/builds/404409816

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

Push gateway image to both Quay.io and Docker Hub

With this change gateway will be pushed to Quay.io on release
as a backup

Signed-off-by: Ivana Yovcheva (VMware) <iyovcheva@vmware.com>

Changes from pull request feedback

1. Use httptest.ResponseRecorder instead of custom implementation
StringResponseWriter.

2. Remove verbose log line in infohandler

Signed-off-by: Edward Wilde <ewilde@gmail.com>