Fix Revit Test failures due to test data restructuring

- Now Revit test data is under test\System\ folder
- Updated all test initialization calls to consider this path for revit
test data.
Fix Revit Test failures due to test data restructuring

- Now Revit test data is under test\System\ folder
- Updated all test initialization calls to consider this path for revit
test data.
Merge pull request #28 from DynamoDS/Revit2015

Cross merge Revit2015 to Revit2016