CI: postgresql job failing
e.g. https://travis-ci.org/pandas-dev/pandas/jobs/612501204

```
installing dbs

psql: could not connect to server: No such file or directory

	Is the server running locally and accepting

	connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

The command "ci/setup_env.sh" failed and exited with 2 during .

Your build has been stopped.
```