Add sleep before JS tests

[phil-davis]

to see if the intermittent JS tests failures are just a startup timing issue

issue #680

[codecov]

Codecov Report

Merging #681 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #681   +/-   ##
=========================================
  Coverage     17.22%   17.22%           
  Complexity        1        1           
=========================================
  Files            57       57           
  Lines          1138     1138           
=========================================
  Hits            196      196           
  Misses          942      942

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 91441f0...0f36586. Read the comment docs.

[phil-davis]

When I restart the nightly drone job it is always passing. And when I restart this drone job it is also always passing. To really be able to test this I need to be able to ensure that the drone pipeline starts on a new drone agent - because it is likely that the timing issue is only going to be a problem onn a new agent that needs to actually fetch ever docker... image from across the network.

[phil-davis]

Nightly results are better since PR #682
No need for a timing hack like this.