feat: Support for Environment to flyway service

[aVolpe]

The FlywayService qbean is helpful to integrate flyway into the life cycle
of the server.

Normally we can migrate the schema automatically in development or local
environments, but in production normally we use a database user with
limited permissions (for example the user can't perform DDL -CREATE,
DROP-).

With this commit you can specify a property as the child of the
tag:

<flyway class="org.jpos.flyway.FlywayService" logger="Q2">
    <property name="out-of-order" value="true" />
    <commands>${flyway_commands:validate}</commands>
</flyway>

This will allow setting an environment variable to local/dev environments
to perform migrations automatically (flyway_commands=migrate).

Signed-off-by: Arturo Volpe arturovolpe@gmail.com