Fix for issue #299 (https://github.com/cbeust/testng/issues/299)

In index.html report, the chronological-class div tag is not closed.
Adding an XMLStringBuffer pop() for the last chronological-class div tag (if any).

modified:   pom-test.xml
modified:   src/main/java/org/testng/reporters/jq/ChronologicalPanel.java