Adding data sanity unit tests for c302 

Four unittest scripts have been added to c302 for data sanity check. Details [here](https://github.com/ahrasheed/CElegansNeuroML/blob/master/CElegans/pythonScripts/c302/unittests/README.md). Slight modifications have been made to SpreadsheetDataReader.py and c302.py to run the scripts. travis.yml only runs unittests, everything else is commented out (as it was giving a build error) please modify it as necessary.