add dry run and output

[mmulholla]

https://issues.redhat.com/browse/APPSVC-1359

Added dry-run flag to create and join commands. For example output:

[INFO] (dry run) SUCCESS: create of Namespace primaza-alice was successful
[INFO] (dry run) SUCCESS: create of CustomResourceDefinition clusterenvironments.primaza.io was successful
[INFO] (dry run) SUCCESS: create of CustomResourceDefinition registeredservices.primaza.io was successful
[INFO] (dry run) SUCCESS: create of CustomResourceDefinition servicebindings.primaza.io was successful
[INFO] (dry run) SUCCESS: create of CustomResourceDefinition servicecatalogs.primaza.io was successful
[INFO] (dry run) SUCCESS: create of CustomResourceDefinition serviceclaims.primaza.io was successful
[INFO] (dry run) SUCCESS: create of CustomResourceDefinition serviceclasses.primaza.io was successful
[ERROR] (dry run) FAILED: create of ServiceAccount primaza-controller-manager: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of Role primaza-claimer: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of Role primaza-leader-election-role: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of Role primaza-manager-role: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of Role primaza-reporter: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of RoleBinding primaza-leader-election-rolebinding: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of RoleBinding primaza-manager-rolebinding: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of ConfigMap primaza-manager-config: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of Service primaza-webhook-service: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of Deployment primaza-controller-manager: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of Certificate primaza-serving-cert: Exception: namespaces "primaza-alice" not found
[ERROR] (dry run) FAILED: create of Issuer primaza-selfsigned-issuer: Exception: namespaces "primaza-alice" not found
[INFO] (dry run) SUCCESS: create of ValidatingWebhookConfiguration primaza-validating-webhook-configuration was successful
Dry run Primaza tenant install complete

Had to skip some checks in the code which rely in the resources being created.

Also added output as yaml option, if specified the only output to stdout is a yaml array of resources created which is similar to kubectl output. If a resource is modified to obscure secret data a warning is output to stderr, for example:
WARNING:Secret primaza-tkn-primaza-alice-cluster1dev: "kubeconfig" attribute modified to hide secrets

Also updated readme and added new tests. The new test also added to PR checks.

[filariow]

some nits

[filariow]

lgtm