babel-runtime is required, but not listed in package.json

[ziktar]

Describe the bug
After adding this issue to my project & compiling, it complained about missing babel-runtime. Installing babel-runtime resolved this issue

To Reproduce
Steps to reproduce the behavior:

1. Create a basic tool without babel-runtime
2. Install tinymce-a11y-checker
3. Build the project
4. See babel-runtime references fail

Expected behavior
All dependencies should be installed by npm install