Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1099988
Description of problem:
When creating a user the --mail option is not required but when updating it is.

Version-Release number of selected component (if applicable):
hammer (0.1.0) * hammer_cli_foreman (0.1.0) * hammer_cli_katello (0.0.3)

How reproducible:
Aways

Steps to Reproduce:
1. # hammer user create --login testuser --password userpasswd --auth-source-id 1
User created
2. # hammer user list --per-page 10000 | grep testuser
48 | testuser | |
3. # hammer user update --id 48 --login usertest
Could not update the user:
Email address can't be blank
4. # hammer user update --id 48 --login usertest --mail test@user.com
User updated
5. # hammer user list --per-page 10000 | grep "48 "
48 | usertest | | test@user.com
Actual results:

Expected results:
If the --mail is required on creation then should ensure that it is filled on update. But if it is not required on creation it should be not required when updating.

Additional info: