Implement user-defined tenant for neutron nets

Default networks were previously hardcoded to use
"admin" as the tenant, regardless of user input.
This patch is a workaround because nailgun creates
neutron_config with admin tenant hardcoded as well.

FIXMEs were added to indicate what code needs cleanup
after nailgun is patched.

Change-Id: I272b53b6dbb4e972f94e82e81b58920351f4144d
Partial-Bug: #1267431

Fix spec test for sanitize neutron config

Added access hash to config to match defaults
for deployment

Change-Id: Ib0ab5f2a532db824572f05c94673be48869fe731
Related-Bug: 1267431
Fix savanna api OS specific log file name

api.log should be used for Centos

Change-Id: I86a1a16e277a08915067efbf6bc2c22d0e50c083
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Merge "Implement user-defined tenant for neutron nets"
Merge "Fix savanna api OS specific log file name"