Fix timeseries import

[mnlevy1981]

Description of changes:

Fixes #175

import timeseries fails when invoking cupid-timeseries, but is valid when running /path/to/CUPiD/cupid/run_timeseries.py so I added a try / except block. There were imports of cupid.util in run_diagnostics.py and clean.py that I changed to this new structure.

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[dabail10]

This looks fine.