Fix For Shadow DOM

So I should release this long time ago... The issue with Shadow DOM has been fixed with some hacks. So you need to specify which element will be the header of the iron-accordion (the one that need to be clicked to reveal the rest).
This is because, before I use *:first-child selector and somehow in Shadow DOM, it doesn't worked as expected.

Initial Working Components

I just want to try release this thing in Bower.