Add device name, ssh password to Tempest config

The following options have been added to the compute section of the
Tempest configuration:

- image_ssh_password
- image_alt_ssh_password
- volume_device_name

The "volume_device_name" is being added to rid the test_attach_volume
test of hardcoded data. In the effort to remove a hardcoded password
from the same test, we introduce the option "image_ssh_password" to
store the password instead. Then, the deprecated "ssh_user" in the
test is swapped out in favor of "image_ssh_user". Finally, we add an
"image_alt_ssh_password" so the option remains symmetrical to the
"image_ssh_password" option.

Closes-Bug: #1220514
Change-Id: If7816e534200c54826c1da0d0464f643163b8657
diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index d39ef70..8d96858 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -76,10 +76,18 @@
 flavor_ref = 1
 flavor_ref_alt = 2
 
-# User names used to authenticate to an instance for a given image.
+# User name used to authenticate to an instance
 image_ssh_user = root
+
+# Password used to authenticate to an instance
+image_ssh_password = password
+
+# User name used to authenticate to an instance using the alternate image
 image_alt_ssh_user = root
 
+# Password used to authenticate to an instance using the alternate image
+image_alt_ssh_password = password
+
 # Number of seconds to wait while looping to check the status of an
 # instance that is building.
 build_interval = 10
@@ -93,7 +101,7 @@
 #  executing the tests
 run_ssh = false
 
-# Name of a user used to authenticated to an instance
+# Name of a user used to authenticate to an instance.
 ssh_user = cirros
 
 # Visible fixed network name
@@ -150,6 +158,9 @@
 # When set to false, flavor extra data tests are forced to skip
 flavor_extra_enabled = true
 
+# Expected first device name when a volume is attached to an instance
+volume_device_name = vdb
+
 [whitebox]
 # Whitebox options for compute. Whitebox options enable the
 # whitebox test cases, which look at internal Nova database state,