William Yeung

My Solution is to modify the default value of `is_training` in sonnet package file [`sonnet/python/modules/nets/convnet.py`](https://github.com/deepmind/sonnet/blob/a6cb7f515f5c670f936f181af3958b2c9a445419/sonnet/python/modules/nets/convnet.py) (line 213) from `None` to `True`.