Merge pull request #17639 from emberjs/dependabot/npm_and_yarn/mocha-6.0.0

Bump mocha from 5.2.0 to 6.0.0

Author: rwjblue

package.json

@@ -147,7 +147,7 @@
     "html-differ": "^1.4.0",
     "lodash.uniq": "^4.5.0",
     "mkdirp": "^0.5.1",
-    "mocha": "^5.2.0",
+    "mocha": "^6.0.0",
     "prettier": "1.16.4",
     "puppeteer": "^1.12.2",
     "qunit": "^2.9.1",