schema: many tests failed

[flaky-bot]

Many tests failed at the same time in this package.

• I will close this issue when there are no more failures in this package and
  there is at least one pass.
• No new issues will be filed for this package until this issue is closed.
• If there are already issues for individual test cases, I will close them when
  the corresponding test passes. You can close them earlier, if you prefer, and
  I won't reopen them while this issue is still open.

Here are the tests that failed:

• should create an avro schema (#1720)
• should create a proto schema
• should create a topic with a schema (#1756)
• should delete a schema (#1757)
• should get a schema (#1758)
• should listen for avro records (#1759)
• should listen for protobuf messages (#1760)
• should list schemas (#1761)
• should publish avro records (#1762)
• should publish protobuf messages (#1763)

---

commit: ac86600
buildURL: Build Status, Sponge
status: failed

[flaky-bot]

Looks like this issue is flaky. 😟

I'm going to leave this open and stop commenting.

A human should fix and close this.

---

When run at the same commit (ac86600), this test passed in one build (Build Status, Sponge) and failed in another build (Build Status, Sponge).