docs(installing-workflow): remove insecure-registry documentation

Author: Matthew Fisher

src/installing-workflow/system-requirements.md

@@ -26,14 +26,10 @@ application footprint as well.
 Running smaller machines will likely result in increased system load and has been known to result in component failures
 and instability.
 
-## Docker Insecure Registry
-
-The on-cluster Docker registry is not deployed with TLS enabled. As such, all Kubernetes worker nodes must have their
-Docker daemons configured to use an **insecure registry**. The configured subnet should encompass any private networks
-used by your worker nodes, including overlay networks.
-
-Depending on your Kubernetes and Docker configuration, setting `EXTRA_DOCKER_OPTS="--insecure-registry=10.0.0.0/8"` may
-be sufficient.
+!!! warning
+	Workflow versions prior to 2.2 require '--insecure-registry' to function properly. Depending on
+	your Kubernetes and Docker configuration, setting
+	`EXTRA_DOCKER_OPTS="--insecure-registry=10.0.0.0/8"` may be sufficient.
 
 ## SELinux + OverlayFS
 

src/quickstart/provider/aws/boot.md

@@ -51,11 +51,6 @@ LICENSES     README.md    Vagrantfile  cluster/     contrib/     docs/        ex
 Before calling the Kubernetes setup scripts, we need to change a few defaults so that Deis Workflow works best. Type
 each of these commands into your terminal application before calling `kube-up.sh`.
 
-First, enable insecure registry support for Docker:
-```
-$ export KUBE_ENABLE_INSECURE_REGISTRY=true
-```
-
 Next, pick the AWS Availability Zone you would like to use. The boot script will create a new VPC in that region.
 
 ```

src/quickstart/provider/vagrant/boot.md

@@ -39,9 +39,9 @@ LICENSES     README.md    Vagrantfile  cluster/     contrib/     docs/        ex
 Before calling the Kubernetes setup scripts, we need to change a few defaults so that Deis Workflow works best. Type
 each of these commands into your terminal application before calling `kube-up.sh`.
 
-First, enable insecure registry support for Docker and use Vagrant as the provider:
+First, use Vagrant as the provider:
+
 ```
-$ export KUBE_ENABLE_INSECURE_REGISTRY=true
 $ export KUBERNETES_PROVIDER=vagrant
 ```