Increase heap size to 256 for elasticsearch
Increase heap size to 256 for elasticsearch

The size of our elasticsearch indices means that 64m is not enough
memory for it to run properly. This commits bumps it to 256m on the
advice of @richardboulton.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet