Get Cirrus's browser tests working

* Add some extra configuration to the Cirrus role that the browser tests
expect
* Remove some overrides in other roles that lower the amount of ram available
to jobs and cause the in process runJobs to fail.
* Add instructions to setup port forwarding for Elasticsearch.
* Remove Elastica submodule update as we're not using a submodule for that
any more.
* Raise RAM to 1G or we won't have room for Elasticsearch and any disk cache.
* Lower Elasticsearch heap space to 256m.  It'll use more then that, but not
too much more.

Change-Id: I893b8f487b3f760fad9962486fd9c668c53cf378