When Django runs the test suite, it creates a new database, in your case test_finance. The postgres user with username django does not have permission to create a database, hence the error message.
When you run migrate or syncdb, Django does not try to create the finance database, so you don’t get any errors.
You can add the createdb permission to the django user by running the following command in the postgres shell as a superuser (hat tip to this stack overflow answer).
=> ALTER USER django CREATEDB;
Note: The username used in the ALTER USER <username> CREATEDB; command needs to match the database user in your Django settings files. In this case, the original poster, had the user as django the above answer.