Update k8s provider default in docs.

Author: dhiller

docs/env-providers.md

@@ -26,7 +26,7 @@ Requires:
 Usage:
 
 ```bash
-export KUBEVIRT_PROVIDER=k8s-1.10.11 # choose this provider
+export KUBEVIRT_PROVIDER=k8s-1.13.3 # choose this provider
 export KUBEVIRT_NUM_NODES=3 # master + two nodes
 make cluster-up
 ```

docs/getting-started.md

@@ -60,7 +60,7 @@ In additional it runs dnsmasq and docker registry containers.
 
 ### Compatibility
 
-The minimum compatible Kubernetes version is 1.10.0. Important features required
+The minimum compatible Kubernetes version is 1.11.0. Important features required
 for scheduling and memory are missing or incompatible with previous versions.
 
 ### Compile and run it
@@ -69,8 +69,8 @@ To build all required artifacts and launch the
 dockerizied environment, clone the KubeVirt repository, `cd` into it, and:
 
 ```bash
-# Build and deploy KubeVirt on Kubernetes 1.10.4 in our vms inside containers
-export KUBEVIRT_PROVIDER=k8s-1.10.11 # this is also the default if no KUBEVIRT_PROVIDER is set
+# Build and deploy KubeVirt on Kubernetes in our vms inside containers
+export KUBEVIRT_PROVIDER=k8s-1.13.3 # this is also the default if no KUBEVIRT_PROVIDER is set
 make cluster-up
 make cluster-sync
 ```