Make stats-box responsive for project pages

[jnbt]

At the moment the table.stats-box on the project page isn't responsive and breaks the layout on smaller devices. This PR wraps the box into a .table-responsive as other tables are already handled.

Before:

After:

[jnbt]

This PR fails on Travis as access_tokens.yml cannot be decrypted.

Perhaps some tests should be skipped for PRs: http://docs.travis-ci.com/user/pull-requests/#Security-Restrictions-when-testing-Pull-Requests

[rrrene]

Nicely done. Thanks!