Shape not implemented yet

[Ontheway361]

PyTorch code：
def forward(self, x):
## x.shape = [B, T, F]
B, _, _ = x.shape
x = x.unsqueeze(1).transpose(2, 3)
x = self.layers(x)
x = torch.mean(x, dim=2, keepdim=True)
x = x.view((B, self.last_channel, -1))
x = x.transpose(1, 2)
return x

when convert onnx model to tflite, builder.py throw a KeyError, maybe we need to implement Shape op.

[MPolaris]

Hi Ontheway361, you can implement it by yourself at first, and welcome PR.