Nested Fragments fail with property does not exist

[jeggy]

Copied from: pgutkowski#50

[nidomiro]

I would say this is fixed with pgutkowski#51
test is here:

KGraphQL/src/test/kotlin/com/apurebase/kgraphql/integration/QueryTest.kt

Line 175 in 1acfb4c

fun `query with nested external fragment`() {