Merge pull request #47 from alexabbott/alex

precompile assets
Merge pull request #48 from alexabbott/alex

Remove D3 and add population density placeholder
Saving changes to the create page so I can pull the latest version
Merge pull request #49 from alexabbott/Brian'sBranch

Added density data to results page and updated bar charts
Consolidated density data, testing performance
Consolidated density data, testing performance
Consolidated density data, testing performance
Merge branch 'Brian'sBranch'
Resolved merge conflicts
Put 12 factor gem back in