Updating to latest cellxgene client code

Fixes the build error in the old version. 

Reverted the API version since we changed directions from updating the API to refactoring the server structure instead.

client/src/reducers/controls.js

@@ -2,7 +2,7 @@
 import _ from "lodash";
 import { parseRGB } from "../util/parseRGB";
 import { createSchemaByDataSniffing } from "../util/schema";
-var crossfilter = require("../util/typedCrossfilter");
+import crossfilter from "../util/typedCrossfilter";
 
 // Deduce the correct crossfilter dimension type from a metadata
 // schema description.