Revert "add method to convert DnsMessage to byte array"

This reverts commit 08efc8bba62b5780e6b608ad69f8885700d6b67e.
Revert "Revert "add method to convert DnsMessage to byte array""

This reverts commit c042fac896e24a8be0f450a686fe068fd79df353.
Merge pull request #1 from tinohager/update1

Update1