Erlang Logger JSON Formatter

Based on Fred Herbert's Flatlog formatter https://github.com/ferd/flatlog

Usage

Add jsonlog as a dependency. Then set this in your sys.config file:

[
  {my_app, []}
  ,{kernel, [
    {logger, [
      {handler, default, logger_std_h,
        #{formatter => {
          jsonlog, #{}
        }}
      }
    ]}
    ,{logger_level, info}
  ]}
].