Downgrade to supported libpq-dev for Trusty
Downgrade to supported libpq-dev for Trusty

The 9.4.* series of libpq-dev seems to have disappeared, so we
switch to 9.3.

project-icp/bee-pollinator-app,project-icp/bee-pollinator-app,project-icp/bee-pollinator-app,project-icp/bee-pollinator-app