Add more function examples for test suite for postgres

[Matthew Peveler]

As part of the work to add better support for redshift, I had to rewrite the getRoutineCreateScript function to manually construct the create function query, as pg_get_functiondef was added in postgres 8.4. However, the existing test case for that function only tests a simple function without any arguments. Should add a function that has arguments to the test suite to test compliance, and that the query does not break in the future.