material-ui

Example app: https://pp0o4x40p0.codesandbox.io/#/posts/13

I just copied the last tab a couple of times and you'll see a scrollbar at the bottom.
What I expected: that the Tabs component would be scrollable and the application not to crash.
I think this is because the Tabs parent width is implicit instead of explicit.
![2018-03-22_09-51-42](https://user-images.githubusercontent.com/621098

I upgraded to v4 and tried to load the page - I'm getting a "window is not defined" error. This is running on a NextJS project (SSR).

Expected Behavior

Dear Mui-treasury contributors,

What is the problem ?
There is a warning while using SwipeableSidebar with Tyepscript:

Warning: React does not recognize the `sidebarId` prop on a DOM element. If you intentionally want it to appear in the DOM as a custom attribute, spell it as lowercase `sidebarid` instead. If you accidentally passed it from a parent component, remove it from the DO