Remove revenue pie chart

Add placeholder for monthly revenue
Add monthly revenue chart
makes revenue-monthly responsive, moves chart heights out of css and into declaration
fixes pie chart label visibility, adds titles to charts, makes border between
charts consistent
Merge branch 'master' into tri-tax
Merge pull request #51 from boonrs/tri-tax

Replace revenue pie chart with monthly revenue chart
Merge branch 'master' into kh-docs