Add ability to toggle the sidebar component with a state parameter

[michaelryancaputo]

Currently there is no way to toggle a sidebar 'show' and 'hide' after it has been mounted to the view.

I would expect (in the case of the expanding drawer) menus that I would be able to toggle the menu open and closed.

[jessy1092]

For current version, you can use init prop for transmit your toggle.

<Sidebar init='toggle'></Sidebar> would transfer 'toggle' to sidebar function: $('.ui.sidebar').sidebar('toggle');

ref. https://github.com/jessy1092/react-semantify/blob/develop/src/modules/sidebar.js#L32

Of course, it is not make sense but I have no time on this issue. I would fix other issue first.
PR is welcome.