Remove baidu

Looks like this repository is no longer available (or private) so
removing it, since it's causing CI to fail:

https://travis-ci.org/github/explore/builds/541595489?utm_source=github_status&utm_medium=notification

Author: talsafran

collections/open-source-organizations/index.md

@@ -20,7 +20,6 @@ items:
  - eleme/eleme.github.io
  - didi/didi.github.io
  - alibaba/alibaba.github.com
- - baidu/baidu.github.io
 display_name: Open source organizations
 created_by: benbalter
 image: open-source-organizations.png