Ajoute depcheck.

.depcheckrc.json

+{
+  "ignore-bin-package": true,
+  "ignores": ["highlight.js", "reveal.js", "esm"]
+}

package.json

@@ -8,7 +8,7 @@
   },
   "scripts": {
     "build": "gulp build",
-    "lint": "eslint ."
+    "lint": "eslint . && depcheck ."
   },
   "repository": {
     "type": "git",
@@ -37,6 +37,7 @@
     "reveal.js": "^3.9.2"
   },
   "devDependencies": {
+    "depcheck": "^0.9.2",
     "eslint": "^6.8.0",
     "eslint-config-prettier": "^6.11.0",
     "eslint-plugin-prettier": "^3.1.3",