Test cases

@pboyer

This submission cleans up some Revit test cases:
1). Some test cases are failing because of they do not consider the precision. This submission will compare the numbers within a given tolerance.
2). Some test cases are failing because the unit is not correct.
3). Some test cases need some Revit files but the model is not specified.
4). For some test cases that are not implemented, they will be marked as to be ignored.