Bump to nats-queue-worker 0.7.0

Includes fix for reconnection bug to NATS Streaming

Signed-off-by: Alex Ellis <[email protected]>

Read config values from environment for max_conns tuning

- max_conns / idle / per host are now read from env-vars and have
defaults set to 1024 for both values
- logging / metrics are collected in the client transaction
rather than via defer (this may impact throughput)
- function cache moved to use RWMutex to try to improve latency
around locking when updating cache
- logging message added to show latency in running GetReplicas
because this was observed to increase in a linear fashion under
high concurrency
- changes tested against 3-node bare-metal 1.13 K8s cluster
with kubeadm

Signed-off-by: Alex Ellis (VMware) <[email protected]>

Revert docker tag bump to 0.10.0

**What**
- Revert to the original docker tags because we want to for the bump
until after the official release

Signed-off-by: Lucas Roesler <[email protected]>

Fix label order for http_requests_total

- the order of http_requests_total was shown to be incorrect in
testing. This fixes the order as per
http_request_duration_seconds.

Signed-off-by: Alex Ellis (VMware) <[email protected]>

Allow unicode in service paths

- according to discussion in openfaas#1013 all unicode characters are
valid label values - this commit allows the original path to be
retained.

Signed-off-by: Alex Ellis (VMware) <[email protected]>

Update swagger for missing secret definitions

- added secret definition and removed types used previously

Remove structs for secrets

- after discussion on PR the core contributors decided we just
want simple CRUD with the Secret type.

Signed-off-by: Alex Ellis (VMware) <[email protected]>

Fix fwatchdog timer memory leak issue

Use timer.AfterFunc to make sure goroutine could be gc.

Signed-off-by: Mike Chiu <[email protected]>

Add sha256 hashgen for watchdog to ci config

Issue openfaas#955 suggested that the watchdog binaries should have associated sha256 files to help assure the veracity of the built artefacts.  This change mirrors the method employed on
faas-cli to generate and deploy the sha256 hash for each flavour of the current watchdog.

Signed-off-by: Richard Gee <[email protected]>

Make use of cache in scaling

- this reinstates the cache to reduce the count of lookups to the
provider when checking if scaling is needed.

Signed-off-by: Alex Ellis (VMware) <[email protected]>

Extract scaling from zero

- extracting this package means it can be used in other components
such as the asynchronous nats-queue-worker which may need to
invoke functions which are scaled down to zero replicas.

Ref: openfaas/nats-queue-worker#32

Tested on Docker Swarm for scaling up, already scaled and not
found error.

Signed-off-by: Alex Ellis (VMware) <[email protected]>