Summary

Re-written the exporter in golang. Taken the opportunity to address a number of defects in the old code base. Requests to the github API should be more efficient and the exporter should execute with a shorter scrape time. This should be non-breaking from the previous config, if you have any issues though then please raise them. As ever, it's recommended running this with an Oauth2 token where possible.

Changes

• Rate limit info now represented in metrics. This is collected at the end of the scrapes through a no-cost call to the rate_limit API endpoint.
• Removed locking, now using constmetrics for Prometheus.
• Added size metric (in KB)