The proto definition of ps needs to be modified

[Kelang-Tian]

elasticdl/elasticdl/proto/elasticdl.proto

Line 118 in 5fac16d

map<string, tensorflow.TensorProto> dense_parameters = 3;

The proto definition is TensorFlow code, and the definition needs to support multiple types.
Maybe general style such as NumPy is a better choice,