Fix crash on "k8s quickstart"

This was due to the recent context refactoring.

See https://discuss.overhang.io/t/error-with-kubernetes-deployment/240

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 Note: Breaking changes between versions are indicated by "💥".
 
+## Unreleased
+
+- [Bugfix] Fix "k8s quickstart" crash
+
 ## 3.9.0 (2019-12-21)
 
 - [Security] Apply django 1.11.21 -> 1.11.27 security patches

tutor/commands/k8s.py

@@ -27,7 +27,7 @@ def quickstart(context, non_interactive):
             " more information."
         )
     click.echo(fmt.title("Updating the current environment"))
-    tutor_env.save(context, config)
+    tutor_env.save(context.root, config)
     click.echo(fmt.title("Starting the platform"))
     start.callback()
     click.echo(fmt.title("Database creation and migrations"))
@@ -69,8 +69,7 @@ def stop(context):
 
 
 @click.command(help="Reboot an existing platform")
-@click.pass_obj
-def reboot(context):
+def reboot():
     stop.callback()
     start.callback()