minor typo in naming

from deepchem.models.tensorgraph import layers

class TestUNet(unittest.TestCase):

class TestResNet50(unittest.TestCase):

  def test_resnet50(self):

    resnet = deepchem.models.tensorgraph.models.resnet50.ResNet50(

    # check output shape

    self.assertEqual(predictions.shape, (2, 1000))

    # new object of UNet to test if loading the model results in same predictions

    resnet_new = deepchem.models.tensorgraph.models.unet.UNet(

        learning_rate=0.003, img_rows=128, img_cols=128, model_dir='./unet/')

    # new object of ResNet to test if loading the model results in same predictions

    resnet_new = deepchem.models.tensorgraph.models.resnet50.ResNet50(

        learning_rate=0.003,

        img_rows=128,

        img_cols=128,

        model_dir='./resnet50/')

    resnet_new.load_from_dir('./resnet50/')

    resnet_new.restore()

    predictions_new = resnet_new.predict(test)