[tests] Jest unit tests fail in node 7.7 #2728

The jest unit tests fail when run in node 7.7 with the error that the global L10N is not available.

Reproduce

• install node 7.7
• git clone https://github.com/devtools-html/debugger.html.git
• yarn
• yarn test

I like using nvm so that i can install a version nvm install 7.7 and then test

Issue

We setup global.L10N here. It's possible this has to do with how Jest uses VM contexts.