Added base chart class that serves as base for all chart types
Added base chart class that serves as base for all chart types

gionkunz/chartist-js,cr3ative/chartist-js,chartist-js/chartist,hansmaad/chartist-js,chartist-js/chartist,gionkunz/chartist-js,hansmaad/chartist-js,cr3ative/chartist-js,chartist-js/chartist