Use 60s resolution in graph

Author: hcho3

dashboard/index.php

@@ -15,15 +15,15 @@
     'MetricName' => 'TodayEC2SpendingUSD',
     'StartTime' => $start_time,
     'EndTime' => $end_time,
-    'Period' => 120,
+    'Period' => 60,
     'Statistics' => array('Maximum')
 ));
 $budget_metric = $client->getMetricStatistics(array(
     'Namespace' => 'XGBoostCICostWatcher',
     'MetricName' => 'DailyBudgetUSD',
     'StartTime' => $start_time,
     'EndTime' => $end_time,
-    'Period' => 120,
+    'Period' => 60,
     'Statistics' => array('Maximum')
 ));