Fix heat template for cassandra

Reasons:
 - heat template for cassandra misses OS::Neutron::Port resource which is 
   required for NICs that can be applied to an instance.

Changes:
 - adding OS::Neutron::Port cassandra heat template.

Change-Id: I9661ae5d6e0695b7fd56d97cc6cd6ab874a3b5d0
Closes-Bug: #1308131
Cleans up ServiceUser.__str__ method

Reasons:
- ServiceUser.__str__ in trove/tests/util/users.py contains code
  after the return statement.
- This code after unconditional return statement has no use.
- Thus, ServiceUser.__str__ method needs cleanup.

Changes:
- Removes the statements after return statement.
- Adds tenant name to the __str__.

Change-Id: Ic5e35969f435e01d94da7eb434cd8de19e2c9873
Closes-Bug: #1269437
Remove admin_token from configs

A previous review removed the admin_token from the sample config file.
It appears that devstack doesn't use that file but instead uses one of
the .test files.

Admin tokens are actively discouraged as a form of authenticating in
auth_token middleware and the behaviour when using admin_token in
combination with a username and password (as this default produces in
devstack) can lead to problems in authentication.

Closes-Bug: #1299332
Change-Id: I78d2c184f7937006b808d580e3663ab055f7c5fe
Merge "Fix heat template for cassandra"
Merge "Cleans up ServiceUser.__str__ method"
Merge "Remove admin_token from configs"