Solve issue with completeness check that fails on empty data

[cr-assafbendavid]

This solve #5 by assuming that if the completeness check data is empty instead of a single line with the expected number of lines, then the expected number of lines is 0.

[MatthiasObserve]

Thanks @cr-assafbendavid for raising this. I found some other issues and have included your code changes in #9