v1.15.1

cbioportal/cbioportal:

• validator fix: Move TUMOR_SITE to patient attribute (#4558)
• validator fix: check hg18 segment files (#4639)
• gene panel fix (#4621)
• Clinical Data Count API fix for multi-sample / multi-study query (#4629)
• Check empty session service (#4640)
• Increase mutation event keyword size (#3012)
• Fix missing db version in db migration sql (#4675)

cbioportal/cbioportal-frontend:

• https://github.com/cBioPortal/cbioportal-frontend/releases/tag/v1.15.1