added view for pie chart
added json view for charts
Added JSON route and linked chart view to it
Switched JSON endpoint to the chart itself to avoid using a separate controller action
added webmock gem
fixed charts spec
added specs for charts API
Mergg branch 'charts' of github.com:chartist/chartist into charts
Refactored specs
Added a test for CSV processing
Added size validation for the uploaded CSV
Added validation for csv files
Merge branch 'charts'
Merged charts branch with master
Fixed merge issues
fixed js bug on turbolinks
Merge issues
merge conflict solved in the template  and .gitignore updated
merge conflict solved
Changed test
Merge branch 'master' of github.com:chartist/chartist