SOLR-6417: OpenCloseCoreStressTest should be much faster on non nightly runs.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1620152 13f79535-47bb-0310-9956-ffa450edef68

solr/core/src/test/org/apache/solr/core/OpenCloseCoreStressTest.java

@@ -104,13 +104,18 @@ public class OpenCloseCoreStressTest extends SolrTestCaseJ4 {
   }
 
   @Test
-  @Slow
+  public void test5Seconds() throws Exception {
+    doStress(5, random().nextBoolean());
+  }
+  
+  @Test
+  @Nightly
   public void test15SecondsOld() throws Exception {
     doStress(15, true);
   }
 
   @Test
-  @Slow
+  @Nightly
   public void test15SecondsNew() throws Exception {
     doStress(15, false);
   }