Update timestamps of test report if running on ci

We have to update the timestamps of our test reports on the ci server,
because Jenkins fails it the reports are older than x minutes.

build-plugins/src/main/groovy/com/cloudogu/scm/TouchFilesTask.groovy

@@ -0,0 +1,46 @@
+package com.cloudogu.scm
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.InputDirectory
+import org.gradle.api.tasks.TaskAction
+
+import java.time.Instant
+
+class TouchFilesTask extends DefaultTask {
+
+  @InputDirectory
+  File directory
+
+  @Input
+  String extension
+
+  @Input
+  long timestamp
+
+  TouchFilesTask() {
+    timestamp = Instant.now().toEpochMilli()
+    // this task should run always
+    outputs.upToDateWhen {
+      false
+    }
+  }
+
+  @TaskAction
+  public void execute() {
+    if (directory.exists()) {
+      touch(directory)
+    }
+  }
+
+  private void touch(File file) {
+    if (file.isDirectory()) {
+      for (File child : file.listFiles()) {
+        touch(child)
+      }
+    } else if (file.getName().endsWith(".${extension}")) {
+      file.setLastModified(timestamp)
+    }
+  }
+
+}