[Feature] Percentage columns in Table Viz (#3586)

* Added percent metric options to table viz

* Added unit tests for TableViz

* fixed code for python3

* bump travis

superset/assets/javascripts/explore/stores/controls.jsx

@@ -100,6 +100,19 @@ export const controls = {
     description: t('One or many metrics to display'),
   },
 
+  percent_metrics: {
+    type: 'SelectControl',
+    multi: true,
+    label: t('Percentage Metrics'),
+    valueKey: 'metric_name',
+    optionRenderer: m => <MetricOption metric={m} />,
+    valueRenderer: m => <MetricOption metric={m} />,
+    mapStateToProps: state => ({
+      options: (state.datasource) ? state.datasource.metrics : [],
+    }),
+    description: t('Metrics for which percentage of total are to be displayed'),
+  },
+
   y_axis_bounds: {
     type: 'BoundsControl',
     label: t('Y Axis Bounds'),

superset/assets/javascripts/explore/stores/visTypes.js

@@ -338,8 +338,9 @@ export const visTypes = {
         label: t('GROUP BY'),
         description: t('Use this section if you want a query that aggregates'),
         controlSetRows: [
-          ['groupby', 'metrics'],
-          ['include_time', null],
+          ['groupby'],
+          ['metrics', 'percent_metrics'],
+          ['include_time'],
           ['timeseries_limit_metric', 'order_desc'],
         ],
       },