fix(@formatjs/cli): allow optionalChaining parser, fix #404

chore(@formatjs/intl-utils): rm unnecessary tests

Author: longlho

package-lock.json

@@ -41,6 +41,7 @@
   },
   "dependencies": {
     "@babel/plugin-proposal-class-properties": "^7.5.5",
+    "@babel/plugin-proposal-optional-chaining": "7",
     "@babel/preset-env": "^7.6.0",
     "@babel/preset-typescript": "^7.6.0",
     "@types/babel__core": "^7.1.3",