HTTP/2 timeouts in Node 12

[iparamonau]

As per #275, there's likely an issue with http/2 in Node 12.

Until this issue is investigated and resolved, please set DISABLE_HTTP2: true in your local config if you start seeing timeouts over HTTPs to disable http/2 if you need node 12 and up.

[iparamonau]

develop branch now includes #344 and the minimum node version will be upped to 14. This issue is resolved and will be released in the next version.