Update mocha

Author: lukemelia

package.json

@@ -4,7 +4,7 @@
   "description": "A Build Plugin for ember-cli-deploy",
   "scripts": {
     "lint:js": "eslint .",
-    "test": "mocha tests/**/*-test.js"
+    "test": "mocha tests/**/*-test.js --exit"
   },
   "engines": {
     "node": "8.* || >= 10.*"
@@ -34,7 +34,7 @@
     "github": "^0.2.4",
     "glob": "^7.1.1",
     "loader.js": "^4.7.0",
-    "mocha": "^3.2.0",
+    "mocha": "^6.2.0",
     "multiline": "^1.0.2"
   },
   "keywords": [