(#6322) - chore(package): update express to version 4.15.0
(#6322) - chore(package): update express to version 4.15.0

https://greenkeeper.io/
seigel/pouchdb,tyler-johnson/pouchdb,seigel/pouchdb,tyler-johnson/pouchdb,tyler-johnson/pouchdb,seigel/pouchdb,pouchdb/pouchdb,cdaringe/pouchdb,pouchdb/pouchdb,cdaringe/pouchdb,cdaringe/pouchdb,pouchdb/pouchdb