Load React + Emotion from CDN URLs, use globals

Remove @emotion/babel-preset-css-prop and import { jsx } from
@emotion/core directly instead so Rollup can preserve imports order when
bundling (instead of @emotion/core automatically inserting itself as the
first import).

public/react-dom@16.7.0/cjs/react-dom-unstable-fizz.node.development.js

@@ -0,0 +1,150 @@
+/** @license React v16.7.0
+ * react-dom-unstable-fizz.node.development.js
+ *
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+'use strict';
+
+
+
+if (process.env.NODE_ENV !== "production") {
+  (function() {
+'use strict';
+
+function scheduleWork(callback) {
+  setImmediate(callback);
+}
+
+function flushBuffered(destination) {
+  // If we don't have any more data to send right now.
+  // Flush whatever is in the buffer to the wire.
+  if (typeof destination.flush === 'function') {
+    // By convention the Zlib streams provide a flush function for this purpose.
+    destination.flush();
+  }
+}
+
+function beginWriting(destination) {
+  destination.cork();
+}
+
+function writeChunk(destination, buffer) {
+  var nodeBuffer = buffer; // close enough
+  destination.write(nodeBuffer);
+}
+
+function completeWriting(destination) {
+  destination.uncork();
+}
+
+function close(destination) {
+  destination.end();
+}
+
+function convertStringToBuffer(content) {
+  return Buffer.from(content, 'utf8');
+}
+
+function formatChunk(type, props) {
+  var str = '<' + type + '>';
+  if (typeof props.children === 'string') {
+    str += props.children;
+  }
+  str += '</' + type + '>';
+  return convertStringToBuffer(str);
+}
+
+// The Symbol used to tag the ReactElement-like types. If there is no native Symbol
+// nor polyfill, then a plain number is used for performance.
+var hasSymbol = typeof Symbol === 'function' && Symbol.for;
+
+var REACT_ELEMENT_TYPE = hasSymbol ? Symbol.for('react.element') : 0xeac7;
+
+function createRequest(children, destination) {
+  return { destination: destination, children: children, completedChunks: [], flowing: false };
+}
+
+function performWork(request) {
+  var element = request.children;
+  request.children = null;
+  if (element && element.$$typeof !== REACT_ELEMENT_TYPE) {
+    return;
+  }
+  var type = element.type;
+  var props = element.props;
+  if (typeof type !== 'string') {
+    return;
+  }
+  request.completedChunks.push(formatChunk(type, props));
+  if (request.flowing) {
+    flushCompletedChunks(request);
+  }
+
+  flushBuffered(request.destination);
+}
+
+function flushCompletedChunks(request) {
+  var destination = request.destination;
+  var chunks = request.completedChunks;
+  request.completedChunks = [];
+
+  beginWriting(destination);
+  try {
+    for (var i = 0; i < chunks.length; i++) {
+      var chunk = chunks[i];
+      writeChunk(destination, chunk);
+    }
+  } finally {
+    completeWriting(destination);
+  }
+  close(destination);
+}
+
+function startWork(request) {
+  request.flowing = true;
+  scheduleWork(function () {
+    return performWork(request);
+  });
+}
+
+function startFlowing(request, desiredBytes) {
+  request.flowing = false;
+  flushCompletedChunks(request);
+}
+
+// This file intentionally does *not* have the Flow annotation.
+// Don't add it. See `./inline-typed.js` for an explanation.
+
+function createDrainHandler(destination, request) {
+  return function () {
+    return startFlowing(request, 0);
+  };
+}
+
+function pipeToNodeWritable(children, destination) {
+  var request = createRequest(children, destination);
+  destination.on('drain', createDrainHandler(destination, request));
+  startWork(request);
+}
+
+var ReactDOMFizzServerNode = {
+  pipeToNodeWritable: pipeToNodeWritable
+};
+
+var ReactDOMFizzServerNode$1 = Object.freeze({
+	default: ReactDOMFizzServerNode
+});
+
+var ReactDOMFizzServerNode$2 = ( ReactDOMFizzServerNode$1 && ReactDOMFizzServerNode ) || ReactDOMFizzServerNode$1;
+
+// TODO: decide on the top-level export form.
+// This is hacky but makes it work with both Rollup and Jest
+var unstableFizz_node = ReactDOMFizzServerNode$2.default || ReactDOMFizzServerNode$2;
+
+module.exports = unstableFizz_node;
+  })();
+}