test_update_envs_env_update is flaky

[ryanjulian]

Command backport release-2020.06: failure

No backport have been created

• Backport to branch release-2020.06 failed

Cherry-pick of a2e8f9e has failed:

On branch mergify/bp/release-2020.06/pr-2056
Your branch is up to date with 'origin/release-2020.06'.

You are currently cherry-picking commit a2e8f9ee.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)

	both modified:   tests/garage/sampler/test_multiprocessing_sampler.py

no changes added to commit (use "git add" and/or "git commit -a")

Originally posted by @mergify in #2056 (comment)

[yeukfu]

https://travis-ci.com/github/rlworkgroup/garage/jobs/385866065