add missing peer

Author: mansona

package.json

@@ -53,6 +53,7 @@
     "@types/ember__utils": "^4.0.2",
     "algoliasearch": "^4.20.0",
     "babel-eslint": "^10.1.0",
+    "bootstrap": "^4.6.2",
     "bourbon": "5.1.0",
     "bourbon-neat": "^1.9.1",
     "broccoli-asset-rev": "^3.0.0",