deis registry:unset unauthorized

```
$ deis version
v2.14.1
````

Setting registry set value works ok:
```
deis registry:set username=adnaan password=dummy --app=myapp
Applying registry information... done

=== myapp Registry
password dummy
username adnaan

````

Unsetting registry values does not:

```
$ deis registry:unset username password --app=myapp
Applying registry information... Error: Unknown Error (400): {"detail":"unauthorized: authentication required"}
```
EDIT:

Is this is the intended behaviour here? I expected this to go through while the release fails.
Thank you!