Merge from master (#328)

* Add default provider taint and taint configuration options

This allows for more specificity when setting taint tolerations for
workloads. Three new env variables are introduced:

VKUBELET_TAINT_KEY (defaults to `virtual-kubelet.io/provider`)
VKUBELET_TAINT_VALUE (defaults to provider name)
VKUBELET_TAINT_EFFECT (defaults to `NoSchedule`)

BREAKING CHANGES:
- The default taint key of `azure.com/aci` is now
  `virtual-kubelet.io/provider`.
- Specifying a custom taint key is now done via an environment variable
  rather than the `--taint` command line flag.

* Add back deprecated taint flag

TODO: Revert this commit

Related to #316

* Add darwin tag to not build for osx

* Darwin specific lookup file without cri and vic

* Fix chart notes template (#317)

Values were moved from env to top level.

* If --taint is specified, set the taint value to empty (#322)

Add the old tolerations the examples to make it backward compatible during the switch

* Use standard logging package (#323)

* Update kubelet vendor to pull in stats API

* Add errgroup dep which will be used for ACI stats

* Add supports for stats in ACI provider

This adds a new, optional, interface for providers that want to provide
stats.

* Don't use globals for API server

Refactors how HTTP servers are started and binds them to objects that
can store the provider rather than relying on a global.

* Fix merge conflict

* Fix couple errors

providers/azure/aci.go

@@ -331,7 +331,7 @@ func (p *ACIProvider) setupNetworkProfile(auth *client.Authentication) error {
 			subnet = &network.Subnet{Name: p.subnetName}
 		}
 		populateSubnet(subnet, p.subnetCIDR)
-		subnet, err = c.CreateOrUpdateSubnet(p.resourceGroup, p.vnetName, subnet)
+		subnet, err = c.CreateOrUpdateSubnet(p.vnetResourceGroup, p.vnetName, subnet)
 		if err != nil {
 			return fmt.Errorf("error creating subnet: %v", err)
 		}
@@ -594,6 +594,10 @@ func (p *ACIProvider) amendVnetResources(containerGroup *aci.ContainerGroup) {
 	containerGroup.ContainerGroupProperties.Volumes = append(containerGroup.ContainerGroupProperties.Volumes, *(p.kubeProxyVolume))
 }
 
+func containerGroupName(pod *v1.Pod) string {
+	return fmt.Sprintf("%s-%s", pod.Namespace, pod.Name)
+}
+
 // UpdatePod is a noop, ACI currently does not support live updates of a pod.
 func (p *ACIProvider) UpdatePod(pod *v1.Pod) error {
 	return nil