Add missing io import in log.py (#1326)

Fixes #1324.

We setup a custom logger for Kaggle kernels.

Some of this logic could be simplified now that we are using Python 3.8+. I filed b/312963888 for this.

b/312961350

Author: rosbo

patches/log.py

@@ -1,3 +1,4 @@
+import io
 import logging
 import os
 
@@ -129,4 +130,4 @@ def _static_init():
         logging.basicConfig(level=logging.INFO, handlers=[handler])
         Log._initialized = True
 
-Log._static_init()
+Log._static_init()