added more xml files that are generating errors when run in production
added a test suite to simply test the structure of the xml and how the gem handles it. Once run in production, it became apparent that the xml is not actually consistent and the parsing was making assumptions that were not correct. These test are to validate how the gem handles these differences.

As errors occur, we can add assertions and use the faculty causing the error as the fixture
add 2 more fixtures to test varieties of faculty
changed env var to a generic "DIGITAL_MEASURES_CREDENTIALS"
extracted retrieving xml strings to a function that handles the xpath not being available
maybe messing up some tests.
added 0.2 version
replaced older tests that were infact fine