Fix CPIO test to not rely on file mode

With different umask when unpacking the archive, the file can have other
mode than expected and this leads to test failure.

This fixes it to expect the same mode as the original file has.

Signed-off-by: Michal Čihař <michal@cihar.com>
Ignore setup generated dirs

Signed-off-by: Michal Čihař <michal@cihar.com>
Support for running tests in Travis CI

Test against more python versions and lxml as well. The build for
current lxml seems to be broken.

Signed-off-by: Michal Čihař <michal@cihar.com>
Fixed XML testing

Test reformatted xml, so that we don't fail in case attributes are
generated in different order. The difference is caused by different
libxml versions behaving differently, so really can not rely on some
order when doing test.

Signed-off-by: Michal Čihař <michal@cihar.com>
Merge branch 'xml-testing' into travis