Fix: warning undefined $USER_AGENT (#14)

fix: use CURLOPT_HEADERFUNCTION for better error handling

fix: throw exception on non-2xx response (#13)

add option devicePixelRatio on toBinary method (thus also toFile) (#11)

closes #10

Co-authored-by: Arnaud <nsslive@hotmail.com>

Set devicePixelRatio in POST request

Add support for Chart.js v3 (#8)

Throw when curl returns error

Use root endpoint in getUrl. Closes #4

Resolve issue about hardcoded endpoint (#3)

* Resolve issue about hardcoded endpoint

* Formatting + exception for short URLs

Co-authored-by: Gabriele Cavigiolo <gabriele.cavigiolo@synesthesia.it>
Co-authored-by: Ian Webster <ianw_github@ianww.com>

PHP5.3 compatibility