update TODO.md
add auths to plugin.yml
give plugins instance to Dispatcher

If you find a better way to do it, please tell me, i’m still a beginner
in Ruby
arrays are good
Ewww, why...
Plugins are now working \o/
Handler is useless for the moment
Plugin can only receives tweet for the moment

I will try to improve this quickly and use auths specified in
plugin.yml of course.
require pathname
just for debug
need update