Added controller file results_graphs.rb

Added route 'results/graph' for displaying graph of survey results
Added helper file results_graphs.rb
Added helper functions for calculating percentages
Added view file results_graphs.erb
Added JS file results_graphs.js for setting widths of graph bars based on data- tags
Added link to survey_results.erb to results/graph route
Added section to application.css to handle display of elements in results_graphs.erb