Workaround postgis error on new travis trusty builds, see https://github.com/travis-ci/travis-ci/issues/6972\#issuecomment-310311276
Workaround postgis error on new travis trusty builds, see https://github.com/travis-ci/travis-ci/issues/6972\#issuecomment-310311276

jonnybarnes/jonnybarnes.uk,jonnybarnes/jonnybarnes.uk,jonnybarnes/jonnybarnes.uk