Thomas Amsler

GRBK-1349 : Grade Scale is sorted by letters instead of numerical values
GRBK-1348 : Apply Spanish translation patch. Thank you very much for the contribution.
GRBK-1345 : adding null checks for assignmentWeight
GRBK-1314 : Apply fix that Chris Schauer has provided. Thank you.
NOJIRA : updating pom version from 1.8.0-SNAPSHOT to 1.9.0-SNAPSHOT
GRBK-1340 : Update dependency library versions
GRBK-1336 : Implemented new LETTER_GRADE_COMPARATOR