Adding DB Migration script for release > 3.20.0 (#1050)
Adding DB Migration script for release > 3.20.0 (#1050)

Context: PR #1024 introduces a new column to 'project_versions' table
reallocf/azkaban,chengren311/azkaban,HappyRay/azkaban,azkaban/azkaban,azkaban/azkaban,HappyRay/azkaban,HappyRay/azkaban,HappyRay/azkaban,sunghyuk/azkaban,erwa/azkaban,sunghyuk/azkaban,erwa/azkaban,HappyRay/azkaban,sunghyuk/azkaban,azkaban/azkaban,chengren311/azkaban,jackrjli/azkaban,jackrjli/azkaban,chengren311/azkaban,erwa/azkaban,HappyRay/azkaban,reallocf/azkaban,jackrjli/azkaban,jackrjli/azkaban,erwa/azkaban,azkaban/azkaban,jackrjli/azkaban,reallocf/azkaban,azkaban/azkaban,chengren311/azkaban,reallocf/azkaban,sunghyuk/azkaban,chengren311/azkaban,sunghyuk/azkaban,erwa/azkaban,reallocf/azkaban,azkaban/azkaban