make it compile again with sbt 0.13.6

build.sbt

@@ -20,7 +20,7 @@ scalacOptions ++= Seq("-deprecation", "-unchecked")
 
 sbt.CrossBuilding.latestCompatibleVersionMapper ~= {
   original => {
-    case "0.13" => "0.13.8"
+    case "0.13" => "0.13.6"
     case x => original(x)
   }
 }

src/main/scala/net/virtualvoid/sbt/graph/backend/SbtUpdateReport.scala

@@ -20,6 +20,10 @@ package backend
 import sbt._
 
 object SbtUpdateReport {
+  type OrganizationArtifactReport = {
+    def modules: Seq[ModuleReport]
+  }
+
   def fromConfigurationReport(report: ConfigurationReport, rootInfo: sbt.ModuleID): ModuleGraph = {
     implicit def id(sbtId: sbt.ModuleID): ModuleId = ModuleId(sbtId.organization, sbtId.name, sbtId.revision)