fix(singlestat): use exact value for coloring

closes #4259

public/app/plugins/panel/singlestat/module.ts

@@ -279,7 +279,7 @@ class SingleStatCtrl extends MetricsPanelCtrl {
 
       if (panel.prefix) { body += getSpan('singlestat-panel-prefix', panel.prefixFontSize, panel.prefix); }
 
-      var value = applyColoringThresholds(data.valueRounded, data.valueFormated);
+      var value = applyColoringThresholds(data.value, data.valueFormated);
       body += getSpan('singlestat-panel-value', panel.valueFontSize, value);
 
       if (panel.postfix) { body += getSpan('singlestat-panel-postfix', panel.postfixFontSize, panel.postfix); }

public/app/plugins/panel/singlestat/specs/singlestat_panel_spec.ts

@@ -24,8 +24,6 @@ describe('grafanaSingleStat', function() {
     });
   });
 
-
-
   describe('negative thresholds', () => {
     var data: any = {
       colorMap: ['green', 'yellow', 'red'],