Prometheus php-fpm exporter

Thanks to @XooR for fixing #26 which resulted in large integers not being marshalled.

Changelog

48c997c ci: release job requires tests to succeed 2f56cf2 ci: Remove workdir for release job 7a8d7a9 ci: Consolidate lint into test d9e3c6f ci: Automatically create a tag upon merge to master 03d8708 fix: json: cannot unmarshal number (#28) 2ff0145 doc: Add isitmaintained.com badge

Docker images

• docker pull hipages/php-fpm_exporter:0.5.1