Review Request 48861: Added preview logo for facebook.

[haosdent huang]

-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/48861/
-----------------------------------------------------------

Review request for mesos, Tomasz Janiszewski, Jie Yu, and Vinod Kone.


Bugs: MESOS-5617
    https://issues.apache.org/jira/browse/MESOS-5617


Repository: mesos


Description
-------

Added preview logo for facebook.


Diffs
-----

  site/source/assets/img/mesos_logo_fb_preview.png PRE-CREATION 
  site/source/layouts/basic.erb d654cab802dd60bc70bafac124d411048800fb7a 

Diff: https://reviews.apache.org/r/48861/diff/


Testing
-------

Example:
![facebook_post](https://issues.apache.org/jira/secure/attachment/12811410/facebook_post.png)


Thanks,

haosdent huang