move files from package_data to MANIFEST

This keeps the extra files included in the distribution, but doesn't
install them into Python's site-packages.

Signed-off-by: Johannes Dewender <github@JonnyJD.net>
make the dummy url opener configurable

It can now return an arbitrary response, or raise an exception.
move creation of the opener into the actual tests, in order
to provide the response or exception
Merge branch 'manifest'

see pull-request #122

Signed-off-by: Johannes Dewender <github@JonnyJD.net>