Implemented predefined VC caching and added VC reference tests.

Change-Id: I84ad56b375f8b076ad92e493775993fc0580249f
diff --git a/core/pom.xml b/core/pom.xml
index 0fa8b97..01dbacd 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -3,7 +3,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>de.ids_mannheim.korap</groupId>
 	<artifactId>Kustvakt-core</artifactId>
-	<version>0.60.5</version>
+	<version>0.61.0</version>
 
 	<properties>
 		<java.version>1.8</java.version>
@@ -223,7 +223,7 @@
 		<dependency>
 			<groupId>de.ids_mannheim.korap</groupId>
 			<artifactId>Koral</artifactId>
-			<version>0.29</version>
+			<version>0.30</version>
 			<exclusions>
 				<exclusion>
 					<groupId>org.eclipse.jetty</groupId>
@@ -275,7 +275,7 @@
 		<dependency>
 			<groupId>de.ids_mannheim.korap</groupId>
 			<artifactId>Krill</artifactId>
-			<version>0.57.0</version>
+			<version>0.58.0</version>
 			<exclusions>
 				<exclusion>
 					<groupId>org.xerial</groupId>