[BUG] ConstructorError module not imported

[Sabri Eyuboglu]

Using version 0.2.0.

import meerkat as mk
import meerkat.nn

dp['emb_col'] = mk.nn.EmbeddingColumn(some 2d np array)

if i save the datapanel and then load it back, i get this error. this was working previously, but i updated the meerkat package this week:

ConstructorError: while constructing a Python object
module 'meerkat.nn.embedding_column' is not imported

[Sabri Eyuboglu]

#185 closes