asyncio_slow: Add example for scheduling coro using Task.

asyncio_slow/test_hello_world_bare.py

@@ -0,0 +1,12 @@
+#import asyncio
+import asyncio_slow as asyncio
+
+@asyncio.coroutine
+def greet_every_two_seconds():
+    while True:
+        print('Hello World')
+        yield from asyncio.sleep(2)
+
+loop = asyncio.get_event_loop()
+asyncio.Task(greet_every_two_seconds())
+loop.run_forever()