Use JDK 8 for maven-surefire-plugin

Changed version in configurations that use JDK 6
since JDK 6 is getting dropped on TC agents.

KTI-2437
diff --git a/libraries/pom.xml b/libraries/pom.xml
index 477943b..83fd9f2 100644
--- a/libraries/pom.xml
+++ b/libraries/pom.xml
@@ -163,7 +163,7 @@
                 <version>${surefire-version}</version>
                 <configuration>
                     <forkMode>once</forkMode>
-                    <jvm>${jdk_1_6}/bin/java</jvm>
+                    <jvm>${jdk_1_8}/bin/java</jvm>
                     <useSystemClassLoader>false</useSystemClassLoader>
                     <useManifestOnlyJar>false</useManifestOnlyJar>
                     <failIfNoTests>false</failIfNoTests>
diff --git a/repo/artifacts-tests/src/test/resources/org/jetbrains/kotlin/kotlin-project/kotlin-project.pom b/repo/artifacts-tests/src/test/resources/org/jetbrains/kotlin/kotlin-project/kotlin-project.pom
index 2b7d34e..138a3d6 100644
--- a/repo/artifacts-tests/src/test/resources/org/jetbrains/kotlin/kotlin-project/kotlin-project.pom
+++ b/repo/artifacts-tests/src/test/resources/org/jetbrains/kotlin/kotlin-project/kotlin-project.pom
@@ -163,7 +163,7 @@
                 <version>${surefire-version}</version>
                 <configuration>
                     <forkMode>once</forkMode>
-                    <jvm>${jdk_1_6}/bin/java</jvm>
+                    <jvm>${jdk_1_8}/bin/java</jvm>
                     <useSystemClassLoader>false</useSystemClassLoader>
                     <useManifestOnlyJar>false</useManifestOnlyJar>
                     <failIfNoTests>false</failIfNoTests>