adderall.internal: Add PyPy support

In PyPy, (is (, ) (, )) fails, while it is true everywhere else, add a
workaround to adderall.internal in order to be able to run on pypy too.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
.travis.yml: Enable pypy

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>