Upgrade mocha library for UI tests (#10692)

* Balance the UI tests job, second half currently 8 min longer * Upgrade mocha to 3.1.0 * rebalance * Remove old mocha

Upgrade mocha library for UI tests (#10692)
e59e8c57 · Matthieu Aubry · GitHub · d4ad50fc · e59e8c57 · e59e8c57
--- a/tests/lib/mocha-3.1.0/test/suite.spec.js
+++ b/tests/lib/mocha-3.1.0/test/suite.spec.js
--- a/tests/lib/mocha-3.1.0/test/test.spec.js
+++ b/tests/lib/mocha-3.1.0/test/test.spec.js
--- a/tests/lib/mocha-3.1.0/test/utils.spec.js
+++ b/tests/lib/mocha-3.1.0/test/utils.spec.js