Do NOT go down to 128mb RAM. Stuff just doesn't work.

puppet apply can't even finish its work.
This was just wrong.
Make use of vagrant-cachier.
Bump up the ES heap.

NB: This setting doesn't get applied until after the ES package is
installed, and then you get two ESes, one with the default
ES_HEAP_SIZE and the other from /etc/default/elasticsearch.
Configure ES unicast across eth1.
Collapse config for readability.