Improved terminal message when the --duration option is used so as …

…to display the number of skipped items with small duration < 0.005s. Fixed pytest-dev#6940

src/_pytest/runner.py

@@ -65,10 +65,11 @@ def pytest_terminal_summary(terminalreporter):
         tr.write_sep("=", "slowest %s test durations" % durations)
         dlist = dlist[:durations]
 
-    for rep in dlist:
+    for i, rep in enumerate(dlist):
         if verbose < 2 and rep.duration < 0.005:
             tr.write_line("")
-            tr.write_line("(0.00 durations hidden.  Use -vv to show these durations.)")
+            tr.write_line("(%s items with duration < 0.005s hidden.  Use -vv to show these durations.)"
+                          % (len(dlist) - i))
             break
         tr.write_line("{:02.2f}s {:<8} {}".format(rep.duration, rep.when, rep.nodeid))