Remove accidental print statement `run_suite_class` (#1007)

Remove print statement used for debugging.

mobly/suite_runner.py

diff --git a/mobly/suite_runner.py b/mobly/suite_runner.py
index 166627f..15f6bc1 100644
--- a/mobly/suite_runner.py
+++ b/mobly/suite_runner.py
@@ -366,7 +366,6 @@
         suite_record.suite_begin()
         runner.run()
         ok = runner.results.is_all_pass
-        print(ok)
       except signals.TestAbortAll:
         pass
     finally: