DOC: added fredapi module to ecosystem list
kind of a shameless plug here, but would love to have my pandas-based project on this page :)
please let me know what you think. Thanks. 

Certainly OK!
 Yep, looks good to me.

As we move towards making pandas-datareader an independent project, we should try to give alternative  data reader projects (like fredapi) equal billing in the pandas docs.
