Unable to install webshim via composer

[shefik]

Trying to install "afarkas/webshim": "1.15.*" via composer throws this error:

Your requirements could not be resolved to an installable set of packages.

Submitting the webshim package at https://packagist.org/packages/submit throws this error:

No composer.json was found in the gh-pages branch.

[Itrulia]

Composer is for .php files, not for assets.

[mekras]

I've created PR to fix this: #539