System Information
Operating system: Ubuntu Linux 18.04.2 LTS amd64
Graphics card: Nvidia Geforce GTX 980

Blender Version
Broken: 2.80 release
Worked: 2.80-445433a6913f

Short description of error
After using Remove Gaps functionality in VSE timeline, audio is not updated and still plays based on state before removing gap.

Exact steps for others to reproduce the error

(Timing below are for illustration and do not need to be exact.)

1. New Video Editing project.
2. Drag audio clip onto timeline (longer than 1 minute for below instructions).
3. Confirm audio plays properly.
4. Cut audio clip at 20 seconds.
5. Cut audio clip at 40 seconds.
6. Delete middle clip (20-40s).
7. Position timeline cursor at 30s.
8. Press Backspace (Remove Gaps). Second audio clip should move left to start at 20s.
9. Position cursor at 15s.
10. Play timeline. Note that audio stops playing at 20s and resumes playing at 40s, even though we have removed the gap. That is, the audio that plays doesn't match the timeline view.
11. Select the audio clip and, in the Source pane, toggle "Caching" one or more times.
12. Play the audio again and see that it what plays now matches what's shown on the timeline.