Changed the train_history_ to be None by default for PrintLayerInfo; this allows us to do things like 'PrintLayerInfo()(net)' instead of 'PrintLayerInfo()(net, None)', which can be useful sometimes.
Changed the train_history_ to be None by default for PrintLayerInfo; this allows us to do things like 'PrintLayerInfo()(net)' instead of 'PrintLayerInfo()(net, None)', which can be useful sometimes.

josephmisiti/nolearn,dnouri/nolearn,BenjaminBossan/nolearn,rubensmachado/nolearn,Adai0808/nolearn,williford/nolearn,cancan101/nolearn,scottlittle/nolearn