Unexplained occasional timeouts

[jcxldn]

• Saucelabs, 30s timeout

• Saucelabs error - tests start but don't run

• https://travis-ci.com/Prouser123/parkrun.js/jobs/292242433

  • Timeout: https://app.eu-central-1.saucelabs.com/tests/c1bb8398ce5342059eb86ae3f7a6dad6#1397
  • Failure: https://app.eu-central-1.saucelabs.com/tests/60bc4e6421ac4897ac64da07c6215973#129

HTTP 504 - https://travis-ci.com/github/Prouser123/parkrun.js/jobs/297436803