fix(postgres): doctest (#473)

Co-authored-by: Vemund Santi <vemund@santi.no>

Author: alexanderankin

modules/postgres/testcontainers/postgres/__init__.py

@@ -45,7 +45,7 @@ class PostgresContainer(DbContainer):
             ...         result = connection.execute(sqlalchemy.text("select version()"))
             ...         version, = result.fetchone()
             >>> version
-            'PostgreSQL 9.5...'
+            'PostgreSQL 16...'
     """
 
     def __init__(