lodash cleanup (#747)

* add own range() function

* lodash cleanup

* remove redundant fill range implementations

* remove use of _.get

* sync test babel config with build

* update tests to match new range implementation

client/src/util/dataframe/labelIndex.js

@@ -3,6 +3,8 @@ Label indexing - map a label to & from an integer offset.  See Dataframe
 for how this is used.
 **/
 
+import { rangeFill as fillRange } from "../range";
+
 /*
 Private utility functions
 */
@@ -21,14 +23,6 @@ function extent(tarr) {
   return [min, max];
 }
 
-function fillRange(arr, start = 0) {
-  const larr = arr;
-  for (let i = 0, l = larr.length; i < l; i += 1) {
-    larr[i] = i + start;
-  }
-  return larr;
-}
-
 /* eslint-disable class-methods-use-this */
 class IdentityInt32Index {
   /*