Switch groupby style.target to string

rreusser · rreusser · commit 3cc16ba55ad5 · 2017-03-10T13:45:06.000-05:00
diff --git a/src/transforms/groupby.js b/src/transforms/groupby.js
@@ -36,7 +36,7 @@ exports.attributes = {
     },
     style: {
         target: {
-            valType: 'any',
+            valType: 'string',
             role: 'info',
             description: [
                 'The group value which receives these styles.'
