Refactor translationRunner.js (#3604)

- Use yargs instead of minimist
- Simplify validators
- Fix typo (RFC5626 -> RFC5646)

package.json

@@ -121,12 +121,12 @@
     "eslint-plugin-jsx-a11y": "^4.0.0",
     "eslint-plugin-react": "^6.10.3",
     "jsdom": "^10.1.0",
-    "minimist": "^1.2.0",
     "mocha": "^3.4.1",
     "react-intl-translations-manager": "^5.0.0",
     "react-test-renderer": "^15.5.4",
     "sinon": "^2.3.2",
-    "webpack-dev-server": "^2.4.5"
+    "webpack-dev-server": "^2.4.5",
+    "yargs": "^8.0.1"
   },
   "optionalDependencies": {
     "fsevents": "*"