Update .mailmap
Update .mailmap

This commit updates .mailmap. This file is useful when we use
`git-shortlog` to get a single author when who uses multiple email
addresses (like me). So, it's better to update the file and keep it
latest as possible.

Change-Id: I530de0b23ff317f817b49e01d51757813a623572

masayukig/tempest,vedujoshi/tempest,masayukig/tempest,vedujoshi/tempest,Juniper/tempest,openstack/tempest,cisco-openstack/tempest,cisco-openstack/tempest,openstack/tempest,Juniper/tempest