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. 

Apologies for some white space changes. Travis build sometimes gives an error (does not fail) as the size of its log file increases more than 4 mb due to the system print statements in c302.py