Scan all methods to inherit super class annotations.

Scan all methods to inherit super class annotations, for `@RiakKey` and `@RiakIndex`
Before it was only scanning declared methods which was ignoring inherited ones, we have an abstract class `RiakKeyValue` which contains template methods including `@RiakKey getKey()` which for us is not a property but calculated, without this change the key is never detected which creates a dynamic Riak key.