Add a JavaScript module -- dashboard.
Implement the chart controls.
Set the initial values for interval and stat.
Fix the prev, next buttons for the horizontal bar chart.
Reduce the top margin to 40 px.
Add x to the grouped x values.
Remove bar chart legend and add hovering tooltip.
Fix the x-ticks on the line chart.
Fix the bar chart x-ticks.
Do more metrics.
Merge pull request #10 from eric-wu/master

Add interaction and fix the x-ticks