Roll SSH key for alext
Roll SSH key for alext

This replaces the ssh key used on one of my machines with a fresh one,
and switches from a DSA key to an RSA one.

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