v1.1.0 - ready for hex.pm

[RTI-2586] Prepare for publishing @ hex.pm (#37)

* Migrate from Makefile to rebar3

* [RTI-2584] Fix travis.yml

* [RTI-2584] The project is not ready for OTP21 yet

* [RTI-2807] Make sure the project is dialyzable

* [RTI-2808] Remove export_all

* [RTI-2806] Add linting with elvis

* [RTI-2806] Address @miriampena's comment

* [RTI-2586] Add relevant hex.pm data