Add ready queue to Worker

This change adds a ready queue in the Worker class, storing components
with non empty inboxes. When stepping components, the ready queue is
utilized to avoid stepping components that are idle, thus increasing
performance drastically.
Make components invoke existing handlers only
Removed backup junk files
set ruby engine directive in gemfile
Use float for timer sleep number
Rename Worker ready queue for clarity
add coverage gem SimpleCov
Add create method to Component
avoid destroying components with filled inboxes
Create broadcasters in Component constructor
Keep track of destroyed state for Components
Add updated Gemfile.lock
Remove redundant assertion when connecting components
Refactor component-connection assertion
Add threaded attack scenario
Add dynamism scenario
Allow calling lowest ancestor handler when stepping
Make Component invoke on_init instead of Worker