replace awesome_print with amazing_print

[jsvd]

the awesome_print library has become inactive and fixes weren't being released, so this PR switches to a new fork called amazing_print!

This will remove the current warning whenever this codec is used for the first time:

The stdin plugin is now waiting for input:
er
/private/tmp/logstash-7.8.0/vendor/bundle/jruby/2.5.0/gems/awesome_print-1.7.0/lib/awesome_print/formatters/base_formatter.rb:31: warning: constant ::Fixnum is deprecated
{
          "type" => "stdin",
       "message" => "er",
      "@version" => "1",
    "@timestamp" => 2020-07-07T10:28:22.493Z,
          "host" => "joaos-mbp.lan"
}

[kares]

👍 wanted to "fix" this for so long