Indent stats.json

see #1079

toolset/benchmark/framework_test.py

@@ -1041,7 +1041,7 @@ class FrameworkTest:
                 # rawData["averageStats"] = self.__calculate_average_stats(test_stats)
                 stats.append(test_stats)
       with open(self.benchmarker.stats_file(self.name, test_type) + ".json", "w") as stats_file:
-        json.dump(stats, stats_file)
+        json.dump(stats, stats_file, indent=2)
 
 
       return results