Check for more packages which may cause problems (facebook#5217)

Author: Timer

scripts/utils/verifyPackageTree.js

@@ -20,6 +20,9 @@ function verifyPackageTree() {
     // These are packages most likely to break in practice.
     // See https://github.com/facebook/create-react-app/issues/1795 for reasons why.
     // I have not included Babel here because plugins typically don't import Babel (so it's not affected).
+    'babel-eslint',
+    'babel-jest',
+    'babel-loader',
     'eslint',
     'jest',
     'webpack',