move data_type definition into BaseData
Warn user that samples are being removed for having too few reads
fix parens in output message for too few mapped reads
Merge branch 'feature/inform_on_dropping_outliers' into dev

* feature/inform_on_dropping_outliers:
  fix parens in output message for too few mapped reads
  Warn user that samples are being removed for having too few reads
  move data_type definition into BaseData