Get tests passing on Windows (and other cleanup)

[bridadan]

This PR does a number of things regarding testing:

• Needed to patch abspath behavior so Linux tests would pass on Windows
• Change how temporary files are created since they are treated differently on Windows. See the following for more information (https://docs.python.org/2/library/tempfile.html#tempfile.NamedTemporaryFile)
• Remove old, incorrect, and/or pointless tests

[coveralls]

Coverage decreased (-2.5%) to 73.168% when pulling 0ee9341 on bridadan:test_cleanup into d4d7f53 on ARMmbed:master.

[theotherjimmy]

Thanks! As for the coverage going down, it looks like it was all false coverage anyway. So this 73% is more accurate than the prior 76%