Move some config variables to app config.
* Remove info function and just use the one that
was used everywhere
* Start using hackney async, this is to protect
the event manager against times where connectivity
to rollbar.com can be slow, or if rollbar is down
* Limit max number of ongoing connections, this
means that if there are lots of reports to send
erollbar will start dropping reports when it runs
out of connections to rollbar.com
* Move all message-related code to
erollbar_parser. This also gets rid of the shared
hrl file
* Remove erollbar_utils, and move the functions
that were being used to the corresponding modules
Update CT part of readme
Add travis ci button
Add test for the handler being up
Merge pull request #15 from omarkj/omarkj-simplification

Omarkj simplification