Support Behalter#apply
Add aliases for Behalter#exec and Behalter#execp
Enable to call function without args with Behalter#call and Behalter#apply
Port EventEmitter from eventemitter2
EventEmitter calls event listener with #apply or #call
Support behavior as an EventEmitter
Merge branch 'feature/behavior-as-event-emitter'
Update to v0.1.0