yarn restore only npm dependencies when package.json is side by side with bower.json

[ptrstpp950]

Do you want to request a feature or report a bug?
A bug.
What is the current behavior?
when I run yarn install only dependencies form package.json are restored. Bower.json dependencies are ignored. When I manually delete package.json, yarn discovers bower.json
If the current behavior is a bug, please provide the steps to reproduce.
Create simple repo with package.json and bower,json. You can clone my https://github.com/ptrstpp950/http2AndWebPerf
What is the expected behavior?
Restore npm dependencies and bower dependencies.
Please mention your node.js, yarn and operating system version.
yarn 16.1
node 6.5.0
windows 10

[nsams]

see #616 and #1247

[sebmck]

Bower is no more, see #1441.