= Don't make test directory a package =

There is a bug in pkgutil that will not find local modules in a directory if
there is also an __init__.py in that directory. This causes the PythonFunction
and FunctionCall (and perhaps other) tests to fail if we put an __init__.py in
this tests directory.  While we should fix pkgutil, the short term fix is to
just not make this directory a package.
