Bar graph added.

node_modules/d3-hierarchy/src/hierarchy/eachBefore.js

@@ -0,0 +1,10 @@
+export default function(callback) {
+  var node = this, nodes = [node], children, i;
+  while (node = nodes.pop()) {
+    callback(node), children = node.children;
+    if (children) for (i = children.length - 1; i >= 0; --i) {
+      nodes.push(children[i]);
+    }
+  }
+  return this;
+}