install PhantomJS, Chart.js and jQuery
Merge branch 'master' into feature/render-chart
generate a chart image
remove document.write
clean up comments
switch chart types
remove jquery
get command-line arguments
create ChartImage module
fix hubot command
change export path
respond tmp files
return an image url
fix : path.exists is now called .
Merge pull request #5 from libinc/feature/render-chart

generate a graph image by chart.js