1, use the pg source and photon spec to build postgres 9.6
2, install 9.6 on the photon 4.0
3, then leverage pg_upgrade to handle the pg major version migration
Signed-off-by: Wang Yan <wangyan@vmware.com>
This commit is to enable data migrator to support migrates data
from mysql to pgsql, this is a specific step for user to upgrade
harbor across v1.5.0, as we have move harbor DB to pgsql from
1.5.0. It supports both harbor and notary db data migration,
and be split into two steps with dependency.
It also fix issue #4847, add build DB migrator in make process.
