For k8s, use provisioner-managed volumes when an absolute host path is not specified. (#741)

In kind, when we bind-mount a host directory it is first mounted into the kind container at /mnt, then into the pod at the desired location.

We accidentally picked this up for full-blown k8s, and were creating volumes at /mnt.  This changes the behavior for both kind and regular k8s so that bind mounts are only allowed if a fully-qualified path is specified.  If no path is specified at all, a default storageClass is assumed to be present, and the volume managed by a provisioner.

Eg, for kind, the default provisioner is: https://github.com/rancher/local-path-provisioner

```
stack: test
deploy-to: k8s-kind
config:
  test-variable-1: test-value-1
network:
  ports:
    test:
     - '80'
volumes:
  # this will be bind-mounted to a host-path
  test-data-bind: /srv/data
  # this will be managed by the k8s node
  test-data-auto:
configmaps:
  test-config: ./configmap/test-config
```

Reviewed-on: cerc-io/stack-orchestrator#741
Co-authored-by: Thomas E Lackey <telackey@bozemanpass.com>
Co-committed-by: Thomas E Lackey <telackey@bozemanpass.com>

stack_orchestrator/deploy/spec.py

@@ -72,8 +72,18 @@ class Spec:
     obj: typing.Any
     file_path: Path
 
-    def __init__(self) -> None:
-        pass
+    def __init__(self, file_path: Path = None, obj={}) -> None:
+        self.file_path = file_path
+        self.obj = obj
+
+    def __getitem__(self, item):
+        return self.obj[item]
+
+    def __contains__(self, item):
+        return item in self.obj
+
+    def get(self, item, default=None):
+        return self.obj.get(item, default)
 
     def init_from_file(self, file_path: Path):
         with file_path:
@@ -81,8 +91,8 @@ class Spec:
             self.file_path = file_path
 
     def get_image_registry(self):
-        return (self.obj[constants.image_resigtry_key]
-                if self.obj and constants.image_resigtry_key in self.obj
+        return (self.obj[constants.image_registry_key]
+                if self.obj and constants.image_registry_key in self.obj
                 else None)
 
     def get_volumes(self):
@@ -118,3 +128,15 @@ class Spec:
 
     def get_capabilities(self):
         return self.obj.get("security", {}).get("capabilities", [])
+
+    def get_deployment_type(self):
+        return self.obj[constants.deploy_to_key]
+
+    def is_kubernetes_deployment(self):
+        return self.get_deployment_type() in [constants.k8s_kind_deploy_type, constants.k8s_deploy_type]
+
+    def is_kind_deployment(self):
+        return self.get_deployment_type() in [constants.k8s_kind_deploy_type]
+
+    def is_docker_deployment(self):
+        return self.get_deployment_type() in [constants.compose_deploy_type]