Chartjs-Data will not draw onto my chart

Maybe could be the version of your Chart.js, here is your code running:

https://jsfiddle.net/6xdvj5u3/

Using this version of Chart.js

https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.1.4/Chart.bundle.min.js

try to take the PabloMartinez’s recommendation adding a header to your PHP file, before your print line:

header('Content-type: application/json');
print json_encode($data);