function createDB(dbName, objectStoreName, t) {
  return new Promise((resolve, reject) => {
    const openRequest = indexedDB.open(dbName);
    t.add_cleanup(() => {
      indexedDB.deleteDatabase(dbName);
    });
    openRequest.onerror = () => {
      reject(openRequest.error);
    };
    openRequest.onsuccess = () => {
      resolve(openRequest.result);
    };
    openRequest.onupgradeneeded = (event) => {
      openRequest.result.createObjectStore(objectStoreName);
    };
  });
}
@description - Function will create a database with the supplied name
               and also create an object store with the specified name.
               If a db with the name dbName exists, this will raze the
               existing DB beforehand.
@param {string} dbName
@param {string} objectStoreName
@param {testCase} t
@returns {Promise} - A promise that resolves to an indexedDB open request