tests: support using PostgreSQL 12

debian/control

@@ -14,8 +14,8 @@ Build-Depends: alembic,
                less,
                links,
                lintian,
-               postgresql-11 | postgresql-9.6 | postgresql-9.4,
-               postgresql-11-debversion | postgresql-9.6-debversion | postgresql-9.4-debversion,
+               postgresql-12 | postgresql-11 | postgresql-9.6 | postgresql-9.4,
+               postgresql-12-debversion | postgresql-11-debversion | postgresql-9.6-debversion | postgresql-9.4-debversion,
                python-all-dev,
                python-apt,
                python-coverage,

integration-tests/runner-lib

@@ -24,7 +24,7 @@
 #   returns: version, e.g. "9.6"
 find-postgresql-version() {
   local status
-  for v in 11 10 9.6 9.4; do
+  for v in 12 11 10 9.6 9.4; do
     status=$(dpkg-query \
              -f'${db:Status-Status} ' \
              -W postgresql-${v} postgresql-${v}-debversion 2>/dev/null || :)