[testing] marking down all jackson related tests as j8+ only

The jackson dep we need for testing is too new a class file to run on j6, stubbing it out too much effort.
Odds we find a bug specifically because this stuff fails on java6/7 are low, and I'm okay with supporting
6/7 a little less well.

test/transform/resource/before/JacksonizedBuilderComplex.java

@@ -1,3 +1,4 @@
+//version 8: Jackson deps are at least Java7+.
 //CONF: lombok.builder.className = Test*Name
 import java.util.List;
 import lombok.Builder;