Fix test-api running unit tests as well

This file was added to support the mocha test explorer in vscode
but it turns out it causes all calls to mocha to run the unit
tests. I couldn't figure out how to ignore through args.

Fixes #3777

.mocharc.yml

@@ -1,11 +0,0 @@
-require:
-  - source-map-support/register
-spec:
-  - out/**/*.test.js
-  - addons/**/out/*.test.js
-watch-files:
-  - out/**/*.js
-  - addons/**/out/*.js
-reporter: spec
-color: true
-check-leaks: true