add some multiprocess and race condition examples

Concurrence_examples/logging_example.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python3
+
+import multiprocessing
+import logging
+import sys
+
+def worker():
+    print 'Doing some work'
+    sys.stdout.flush()
+
+if __name__ == '__main__':
+    multiprocessing.log_to_stderr(logging.DEBUG)
+    p = multiprocessing.Process(target=worker)
+    p.start()
+    p.join()