[fix] allow peer authentication for user "postgres" when running CI jobs

Author: hemache

Diff for: .travis.yml

@@ -39,6 +39,7 @@ before_install:
   - sudo apt-get install binutils libproj-dev gdal-bin -y
   - sudo cat /var/log/postgresql/postgresql-12-main.log
   - sudo sed -i 's/port = 5433/port = 5432/' /etc/postgresql/12/main/postgresql.conf
+  - sudo sed -i -e '/local.*peer/s/postgres/all/' -e 's/peer\|md5/trust/g' /etc/postgresql/12/main/pg_hba.conf
   - sudo systemctl restart postgresql@12-main
   - sudo cat /var/log/postgresql/postgresql-12-main.log
   - pip install -U pip setuptools wheel