extracted out generic Segment tests to SegmentTests so they can be reused
test converting Segment to numpy array
added pct_diff function with tests
changed floating point comparison from assertEqual to assertTrue for percent diff less than 0.1 percent
fixed tests_iterable to work will all data
have ReaderTests subclass SegmentTests
cleaned up test_convert_numpy_array
made Segment new style class
made subclass of Segment
updated so it works as subclass of Segment. Tests pass
added tests /implemented handling zeros in pct_diff
get len from first index in shape
moved slicing to segment tests
implemented hekaReader