Fix unit tests failing in some cases

TestZeroCopy used to fail when 'localhost' resolved to an ipv6
address. https://github.com/eventlet/eventlet/issues/8

Also, "test_container_sync_realms.py:TestUtils.test_os_error"
used to fail when unit tests were run as root user. This is
because despite os.chmod(), a root user still has permission
to access the file and hence OSError is not raised.

Change-Id: Ife80b203358557999734515261814ce76c0e00cd
Signed-off-by: Prashanth Pai <ppai@redhat.com>
Merge "Fix unit tests failing in some cases"