Add tests for index creation
Add tests for index creation

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