Add SSR streaming API and stuff

.eslintignore

@@ -4,4 +4,5 @@ coverage/
 node_modules/
 stylis.js
 /demo/dist
-/packages/site/build
+/packages/site/build
+flow-typed/

.flowconfig

@@ -19,3 +19,4 @@ module.name_mapper='^\(emotion\)$' -> '<PROJECT_ROOT>/packages/\1/src'
 module.name_mapper='^\(babel-plugin-emotion\)$' -> '<PROJECT_ROOT>/packages/\1/src'
 module.name_mapper='^\(emotion-theming\)$' -> '<PROJECT_ROOT>/packages/\1/src'
 module.name_mapper='^\(emotion-server\)$' -> '<PROJECT_ROOT>/packages/\1/src'
+module.name_mapper='^\(create-emotion-server\)$' -> '<PROJECT_ROOT>/packages/\1/src'

docs/ssr.md

@@ -2,6 +2,30 @@
 
 Server-Side Rendering in emotion currently does not work with `extractStatic`. It's similar to [glamor's api](https://github.com/threepointone/glamor/blob/master/docs/server.md). For an example of emotion and next.js checkout the [with-emotion example in the next.js repo](https://github.com/zeit/next.js/tree/master/examples/with-emotion).
 
+### renderStylesToString
+This returns a string of html that inlines the critical css required right before it's used.
+
+```jsx
+import { renderToString } from 'react-dom/server'
+import { renderStylesToString } from 'emotion-server'
+import App from './App'
+
+const html = renderStylesToString(renderToString(<App />))
+```
+
+
+### renderStylesToNodeStream
+This returns [Node Stream Writable](https://nodejs.org/api/stream.html#stream_class_stream_writable) that can be used to insert critical css right before it's required. This can be used with [React's streaming API](https://reactjs.org/docs/react-dom-server.html#rendertonodestream).
+
+```jsx
+import { renderToNodeStream } from 'react-dom/server'
+import { renderStylesToNodeStream } from 'emotion-server'
+import App from './App'
+
+const stream = renderToNodeStream(<App />).pipe(renderStylesToNodeStream())
+```
+
+
 ### extractCritical
 This returns an object with the properties `html`, `ids` and `css`. It removes unused rules that were created with emotion(it still includes rules that were inserted with `injectGlobal`).
 
@@ -11,12 +35,12 @@ import { extractCritical } from 'emotion-server'
 import App from './App'
 
 
-const { html, ids, css } = extractCritical(renderToString(<App/>))
+const { html, ids, css } = extractCritical(renderToString(<App />))
 
 ```
 
 #### hydrate
-`hydrate` should be called on the client with the `ids` that `extractCritical` returns. If you don't call it then emotion will reinsert all the rules.
+`hydrate` should be called on the client with the `ids` that `extractCritical` returns. If you don't call it then emotion will reinsert all the rules. `hydrate` is **only** required for `extractCritical`, **not** for `renderStylesToString` or `renderStylesToNodeStream`, hydration occurs automatically with `renderStylesToString` and `renderStylesToNodeStream`.
 
 ```jsx
 import { hydrate } from 'emotion'