usage multiple schema test case / code example

[eflauzo]

Project is looking very interesting, but it misses example how to load multiple avro schemas and then use them.

I can not see in test cases example where one would load few avro schemas where one is depended on another, and then serialize/deserialize message.

[serejja]

Hey @eflauzo, thank you and Michael for providing me with some of your work. I managed to integrate some of your code into go-avro now, maybe will add some more stuff a bit later. For now (regarding this issue) I've added some code examples showing how to use schema loading.

Thanks!