Unable to extend ejabberd with mod_offline hook

I am seeing the following exception when I bring up ejabberd, I have defined the following in my ejabberd.yml

mod_offline_post:
auth_token: "offline_post_auth_token"
post_url: "http://localhost:4567/offline_post"

I am trying to use https://github.com/adamvduke/mod_interact for handling offline messages..
Any help will be appreciated, unable to do development because of this issue.

Thanks,

Kasi

Error message in log file:

2016-05-15 18:06:12.014 [error] <0.37.0> CRASH REPORT Process <0.37.0> with 0 neighbours exited with reason: call to undefined function mod_offline_post:mod_opt_type(db_type) in application_master:init/4 line 134
2016-05-15 18:06:12.014 [info] <0.7.0> Application ejabberd exited with reason: call to undefined function mod_offline_post:mod_opt_type(db_type)