fixed json syntax in vendor.json
fixed json syntax in vendor.json

4dn-dcic/fourfront,4dn-dcic/fourfront,hms-dbmi/fourfront,hms-dbmi/fourfront,hms-dbmi/fourfront,hms-dbmi/fourfront,hms-dbmi/fourfront,4dn-dcic/fourfront,4dn-dcic/fourfront