refactor tests to work better with latest mocha and node

No more mixed imports/requires

Author: nfrasser

.mocharc.yml

@@ -1 +1,4 @@
-require: '@babel/register'
+ignore:
+  - 'test/qunit/*'
+  - 'test/conf.js'
+  - 'test/*.conf.js'

babel.config.js

@@ -18,7 +18,8 @@
     "lint": "eslint .",
     "format": "prettier --plugin-search-dir . --write .",
     "prepack": "npm run prepack --workspaces",
-    "test": "mocha test/index.js",
+    "pretest": "npm run build --workspace linkifyjs --silent",
+    "test": "mocha --file test/setup.js --recursive",
     "test:coverage": "nyc --reporter=lcov --reporter=text mocha test/index.js",
     "test:ci": "run-s test:ci1 test:ci2",
     "test:ci1": "karma start test/ci1.conf.js --single-run",