exciting changes - upgrade to rebar3 !!

Merge pull request #56 from esl/feature/upgrade-to-rebar3

Feature/upgrade to rebar3

Change in clear notifications, new API function

• new API function elarm:clear/4 to add the reason why the alarm was cleared; no other API changes

 elarm:clear(Server, AlarmId, Source, ClearReason)

• Elarm sends the event for clear and manual clear in the same format

  {elarm, Ref, {clear, alarm_id(), alarm_src(), event_id(), Reason}}
  when Reason :: ok | {manual, UserId} | source_gone | term()

Stability fixes

Merge pull request #34 from dszoboszlay/master

Fix compilation issues

Version 0.1.0

Merge pull request #21 from hcs42/master

Fix copyright header