[BUG] merlin info should generate key

[ben-bay]

🐛 Bug Report

Describe the bug
Even with the proper results backend password in app.yaml, a run of merlin info shows the results backend as not working because encrypt_data_key has not yet been generated.

To Reproduce
Steps to reproduce the behavior:

1. Remove encrypt_data_key from merlin home dir.
2. Run merlin info
3. See authentication error

Expected behavior
merlin info should generate its own encrypt_data_key if one does not yet exist.

[koning]

I do not see an authentication error when I remove the key.

[ben-bay]

You're right, this behavior isn't as clear-cut as I originally thought.

[koning]

I think we should add encryption.init_key() to the celery config creation step.