Use a better logstash pipeline filter

[shazChaudhry]

elk/logstash/config/pipeline/logstash.conf

# The following filter is a hack! The "de_dot" filter would be better.
filter {
  ruby {
    code => "
      event.to_hash.keys.each { |k| event[ k.gsub('.','_') ] = event.remove(k) if k.include?'.' }
    "
  }
}