Updated expectation to changed DOM XML generation
Mark mediawiki tests as incomplete

Test suite is only executed because of new configuration – was not
supposed to be run yet.
Mark tests slow

These test load additional styles from the internet and are damn slow
because of this. This allows to exclude them from the current test run.
Fixed locating images in tests

The current working dir changed because of the modified PHPUnit
configuration. This fixes the tests without modifying the input binary
data.
Fixed test case
Added: Basic travis configuration