Add keyRange factory
Add keyRange factory

jayfunk/IDBWrapper,kilbot/IDBWrapper,kilbot/IDBWrapper,safetychanger/IDBWrapper,jayfunk/IDBWrapper,GerHobbelt/IDBWrapper,mizchi/idb-wrapper-promisify,mizchi/idb-wrapper-promisify,jensarps/IDBWrapper,rubenstolk/IDBWrapper,jensarps/IDBWrapper,safetychanger/IDBWrapper,rubenstolk/IDBWrapper