test: Fix minor issues with tests.

Author: timoxley

src/utils/PushQueue.ts

@@ -226,8 +226,6 @@ export default class PushQueue<T> {
             // for next()
             this.error = err
         }
-
-        await this._cleanup()
     }
 
     get length() {

test/flakey/LongResend.test.ts

@@ -1,5 +1,5 @@
 import { wait } from 'streamr-test-utils'
-import { StreamrClient, Stream } from '../../src'
+import StreamrClient, { Stream } from '../../src'
 import { fakePrivateKey } from '../utils'
 import Connection from '../../src/Connection'
 import prettyBytes from 'pretty-bytes'