Update umapi.py

[Luci2015]

Summary

• A fix to handle the remove/delete of accounts with different email than username (both having email formatted values), when the input is a csv list
• Modifies the behaviour so that when writing to csv file (--write-file) contains the mail value of the account instead of the username

Testing Steps

• have in admin console an account with different email than username
• run the tool with --adobe-only-user-action write-file a.csv argument
• look inside at the resulting .csv username field -> it should be the current account's email, that the API will use further for other action.
• run the tool with --adobe-only-user-action delete --adobe-only-user-list a.csv and the account should get deleted from admin console

Fixes #808

[adorton-adobe]

Thank you for this but I've decided to take a different approach. Since the central issue is that the email address is needed to identify the user for the UMAPI call, I've modified the CSV write function to write the email address instead of the username. The read function now checks for email primarily and only uses username if email is not provided.

As a consequence of this change, I updated the user key format to include email address.

The main changes are here - 651d211

I've also updated all tests that were impacted by the key format change.