1080609 - pulp-manage-db now ensures the admin.

[bowlofeggs]

The webserver used to create the admin role and user if it didn't exist
upon startup. Once Pulp started to be deployed to multiple processes,
this caused a uniqueness constraint to be raised during the first
startup of Apache, as each process raced to create the admin user
simultaneously.

This commit moves the admin role and user creation into the
pulp-manage-db script.

https://bugzilla.redhat.com/show_bug.cgi?id=1080609

[jortel]

LGTM

One comment pertaining to the two managers involved here (which I know you did not write). I'm not a fan of checking to see if something exists before creating it in concurrent systems. I would favor catching the duplicate key instead which would account for race conditions.

[bowlofeggs]

Yeah I agree with that in general. This shouldn't affect us anymore since we are using pulp-manage-db in these particular cases, so I will avoid refactoring those methods at this time. Thanks!