Merge pull request #48 from llh1/uat

Reracking fix
Set the correct purpose_id depending on the role of the plate
Add STOCK_RNA_PLATE_PURPOSE_ID constant and update update_plate method
Fix spec
Bump version to 1.1.3
Fix order handler
Merge pull request #49 from llh1/55154924_rna_racks_need_to_be_created_as_rna_stock_plates_in_ss

55154924 rna racks need to be created as rna stock plates in ss
Merge from development 1.1.3