optional csv logging to get rid of strict Cassandra dependency

@airbnb/di 
Added optional job status logging to remove strict Cassandra dependency.
This puzzles me too. If I do not have "== true" I got following compile error in Intellij

Error:(11, 16) type mismatch;
 found   : org.rogach.scallop.ScallopOption[Boolean]
 required: Boolean
    if (config.useCassandraLogJobStats) {
               ^