Update CRD specs to use apiextensions v1

**What**
* Update helm chart RBAC templates to use the `rbac.authorization.k8s.io/v1` group. The beta groups will be removed in k8s 1.20
* Update CRD artifacts using the lastest generator: `./hack/update-crds.sh`
* Update helm chart yaml to use the new CRD specs that live in the `apiextensions.k8s.io/v1` group. The beta groups will be removed in k8s 1.19
* Update Chart readme with a section about service meshes

Test the installation via

```sh
$ kind create cluster
$ helm upgrade openfaas --install chart/openfaas/ \
    --namespace openfaas \
    --set basic_auth=false \
    --set functionNamespace=openfaas-fn
Release "openfaas" does not exist. Installing it now.
NAME: openfaas
LAST DEPLOYED: Sat Nov 14 17:11:59 2020
NAMESPACE: openfaas
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
To verify that openfaas has started, run:

  kubectl -n openfaas get deployments -l "release=openfaas, app=openfaas"
$ kubectl api-versions | grep openfaas
openfaas.com/v1
$ kubectl get crds
NAME                    CREATED AT
profiles.openfaas.com   2020-11-14T16:11:59Z
```

Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>

artifacts/crds/openfaas.com_functions.yaml

@@ -1,8 +1,8 @@
-apiVersion: apiextensions.k8s.io/v1beta1
+apiVersion: apiextensions.k8s.io/v1
 kind: CustomResourceDefinition
 metadata:
   annotations:
-    controller-gen.kubebuilder.io/version: v0.3.0
+    controller-gen.kubebuilder.io/version: v0.4.0
   creationTimestamp: null
   name: functions.openfaas.com
 spec:
@@ -13,81 +13,80 @@ spec:
     plural: functions
     singular: function
   scope: Namespaced
-  validation:
-    openAPIV3Schema:
-      description: Function describes an OpenFaaS function
-      type: object
-      required:
-      - spec
-      properties:
-        apiVersion:
-          description: 'APIVersion defines the versioned schema of this representation
-            of an object. Servers should convert recognized schemas to the latest
-            internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
-          type: string
-        kind:
-          description: 'Kind is a string value representing the REST resource this
-            object represents. Servers may infer this from the endpoint the client
-            submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
-          type: string
-        metadata:
-          type: object
-        spec:
-          description: FunctionSpec is the spec for a Function resource
-          type: object
-          required:
-          - image
-          - name
-          properties:
-            annotations:
-              type: object
-              additionalProperties:
-                type: string
-            constraints:
-              type: array
-              items:
-                type: string
-            environment:
-              type: object
-              additionalProperties:
-                type: string
-            handler:
-              type: string
-            image:
-              type: string
-            labels:
-              type: object
-              additionalProperties:
-                type: string
-            limits:
-              description: FunctionResources is used to set CPU and memory limits
-                and requests
-              type: object
-              properties:
-                cpu:
+  versions:
+  - name: v1
+    schema:
+      openAPIV3Schema:
+        description: Function describes an OpenFaaS function
+        type: object
+        required:
+        - spec
+        properties:
+          apiVersion:
+            description: 'APIVersion defines the versioned schema of this representation
+              of an object. Servers should convert recognized schemas to the latest
+              internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
+            type: string
+          kind:
+            description: 'Kind is a string value representing the REST resource this
+              object represents. Servers may infer this from the endpoint the client
+              submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
+            type: string
+          metadata:
+            type: object
+          spec:
+            description: FunctionSpec is the spec for a Function resource
+            type: object
+            required:
+            - image
+            - name
+            properties:
+              annotations:
+                type: object
+                additionalProperties:
                   type: string
-                memory:
+              constraints:
+                type: array
+                items:
                   type: string
-            name:
-              type: string
-            readOnlyRootFilesystem:
-              type: boolean
-            requests:
-              description: FunctionResources is used to set CPU and memory limits
-                and requests
-              type: object
-              properties:
-                cpu:
+              environment:
+                type: object
+                additionalProperties:
                   type: string
-                memory:
+              handler:
+                type: string
+              image:
+                type: string
+              labels:
+                type: object
+                additionalProperties:
                   type: string
-            secrets:
-              type: array
-              items:
+              limits:
+                description: FunctionResources is used to set CPU and memory limits
+                  and requests
+                type: object
+                properties:
+                  cpu:
+                    type: string
+                  memory:
+                    type: string
+              name:
                 type: string
-  version: v1
-  versions:
-  - name: v1
+              readOnlyRootFilesystem:
+                type: boolean
+              requests:
+                description: FunctionResources is used to set CPU and memory limits
+                  and requests
+                type: object
+                properties:
+                  cpu:
+                    type: string
+                  memory:
+                    type: string
+              secrets:
+                type: array
+                items:
+                  type: string
     served: true
     storage: true
 status: