Documentation fixes

There are three doc fixes for builders.py  in this change.

Link to Gradle plugin fixed
Maven-target example has been fixed
Copyartifact docs cleaned up

Change-Id: Ie50e94ace2041735cc986eb117597262b40b0fa5
Reviewed-on: https://review.openstack.org/25962
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins
Add support for the MultiJob plugin

Change-Id: Ie6c06072eae17fddf241fa0bc416d20c9a2248dc
Reviewed-on: https://review.openstack.org/26321
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins
`test` can now takes several job names

Make the test command to accept several job names. This is exactly like
the change I have made for `update` in 4f5cfb1 (and fixed in fc86fbe).

Change-Id: I68d634b29e4a8ff16818ddeb6f90c7ff072c93a5
Reviewed-on: https://review.openstack.org/26838
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins
Add suport for the Publish over SSH plugin.

Change-Id: Id06bd57c1d290df98c05b3cb19066013635199a3
Reviewed-on: https://review.openstack.org/26831
Reviewed-by: James E. Blair <corvus@inaugust.com>
Approved: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins