convert capitalization scheme to sentence case

app/assets/javascripts/burndown_chart/index.js

@@ -23,7 +23,7 @@ $(() => {
     const chart = new BurndownChart({ container, startDate, dueDate });
 
     let currentView = 'count';
-    chart.setData(openIssuesCount, { label: 'Open Issues', animate: true });
+    chart.setData(openIssuesCount, { label: 'Open issues', animate: true });
 
     $('.burndown-header').on('click', '.btn', function switchData() {
       const $this = $(this);
@@ -33,10 +33,10 @@ $(() => {
         $this.addClass('active').siblings().removeClass('active');
         switch (show) {
           case 'count':
-            chart.setData(openIssuesCount, { label: 'Open Issues', animate: true });
+            chart.setData(openIssuesCount, { label: 'Open issues', animate: true });
             break;
           case 'weight':
-            chart.setData(openIssuesWeight, { label: 'Open Issue Weight', animate: true });
+            chart.setData(openIssuesWeight, { label: 'Open issue weight', animate: true });
             break;
           default:
             break;

app/views/shared/milestones/_burndown.html.haml

@@ -10,12 +10,12 @@
 - if burndown&.valid?
   .burndown-header
     %h3
-      Burndown Chart
+      Burndown chart
       .btn-group
         %button.btn.btn-xs.active{ data: { show: 'count' } }
           Issues
         %button.btn.btn-xs{ data: { show: 'weight' } }
-          Issue Weight
+          Issue weight
   .burndown-chart{ data: { start_date: milestone.start_date.strftime("%Y-%m-%d"), due_date: milestone.due_date.strftime("%Y-%m-%d"), chart_data: burndown.chart_data.to_json } }
 
 - elsif can?(current_user, :admin_milestone, @project) && cookies['hide_burndown_message'].nil?
@@ -26,7 +26,7 @@
         = custom_icon('icon_burndown_chart_splash')
       .col-sm-8.col-xs-12.inner-content
         %h4
-          Burndown Chart
+          Burndown chart
         %p
           View your milestone's progress as a burndown chart.  Add both a start and a due date to
           this milestone and the chart will appear here, always up-to-date.