CircleCI: Persist frontend artifacts
CircleCI: Persist frontend artifacts

Instead of building them in each job. Build them only in install phase. Then
attach that volume again in the other jobs.


Former-commit-id: 2c774d0fc25f6b6b614a48b48aff358263e2fef7
cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend