add admin server tests

- use regular user to resize vm in test_resize_server_using_overlimit_*
- rebuild server when it's in SHUTOFF and ERROR state
- add parameter 'raise_on_error' in wait_for_server_status

Change-Id: Ibd04a1fdaab74fe59bcf16cc99d4ecf4821f4ae2
Fix display_name of volume for test_volumes_list

In test_volumes_list, three volumes are created for some tests.
These display_name seems wrong like "volume-%s1393726625json".
The interface name should be inserted after "volume-", but it is
appended to the tail.
This patch fixes this volume name.

Change-Id: Iee55d2405e888569455a2325fe6b2843ddf9de9d
Merge "add admin server tests"
Merge "Fix display_name of volume for test_volumes_list"
Rename create_test_server to create_temp_server

Change https://review.openstack.org/#/c/58645/ introduced bug 1247161 when
running under nose as the method name includes "test".
Renamed to not use test and updated HACKING to give advice against using
"test" in a method name.

Closes-bug: 1247161

Change-Id: I9f6d7d5fc9b3b94e1fbf395a62177c8df7e9f5b4