Added few test polypeptide features
Added support for Dervies_from attribute
Added bunch of unit tests for the polypeptide features
Added feature relationship tests for the polypeptide features
Updated tests for doing row counts in different chado tables
Added tests for dervies_from relation of polypeptides
Added feature count based on feature type
Added one feature count and few location based unit tests for
polypeptide features
Added a check for SO before loading the GFF3 file
fixed syntax error in SQL statement
Merge pull request #146 from dictyBase/feature/import-polypeptide

Feature/import polypeptide