Fix recurrent construct graph

Author: Laicheng0830

tensorlayerx/nn/core/common.py

@@ -540,7 +540,8 @@ def construct_graph(inputs, outputs):
                 if out_node.node_name not in indegrees.keys():
                     indegrees[out_node.node_name] = len(out_node.in_nodes)
                 indegrees[out_node.node_name] -= 1
-                if indegrees[out_node.node_name] == 0:
+                if indegrees[out_node.node_name] == 0 or \
+                        isinstance(out_node.layer, (tlx.nn.RNN, tlx.nn.LSTM, tlx.nn.GRU)):
                     next_depth.append(out_node)
         cur_depth = next_depth
         next_depth = []

tensorlayerx/nn/layers/activation.py

@@ -438,6 +438,7 @@ class Softmax(Module):
     def __init__(self, axis = -1):
         super(Softmax, self).__init__()
         self._built = True
+        self.axis = axis
         self._softmax = tlx.ops.Softmax(axis)
 
     def forward(self, x):