Cleanup dataset tests. Most of these are only unit tests so do not need full objects.
Cleanup dataset tests. Most of these are only unit tests so do not need full objects.

T2DREAM/t2dream-portal,ENCODE-DCC/encoded,hms-dbmi/fourfront,ENCODE-DCC/snovault,ENCODE-DCC/encoded,hms-dbmi/fourfront,ENCODE-DCC/snovault,T2DREAM/t2dream-portal,4dn-dcic/fourfront,4dn-dcic/fourfront,hms-dbmi/fourfront,ENCODE-DCC/snovault,ENCODE-DCC/snovault,hms-dbmi/fourfront,4dn-dcic/fourfront,T2DREAM/t2dream-portal,ENCODE-DCC/encoded,hms-dbmi/fourfront,4dn-dcic/fourfront,T2DREAM/t2dream-portal,ENCODE-DCC/snovault,ENCODE-DCC/encoded