Moved test script so unit tests won't find it.

Moved
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* Moved test_script_for_fastscape_stream_power into examples folder
  so the unit tests won't find it.

Changed
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* Updated the location of the input DEM to match the new location of the
  test script.
Merge pull request #26 from mcflugen/fix-unit-tests

Moved test script so unit tests won't find it.