Addition of nlu_core_server.py

[ashhadulislam]

Introduced a new file called nlu_core_server.py inside the folder "Full Code [Latest release of Rasa NLU and Rasa Core]"
This code when executed, runs a a simple web server at a port number specified in the code itself.
This local server that can send responses according to the questions sent to it.

Example url:http://localhost:5003/chat/
url_type:POST
request body type:raw(application/json)
sample request:{ "sender": "user1", "message": "how is the weather in Dublin"}
For every unique "sender", a different chat thread is maintained by the server so that the conversation is unique to each client.

Response would be a json containing the string:
"It is currently Sunny in Dublin at the moment. The temperature is 23.0 degrees, the humidity is 50% and the wind speed is 8.1 mph."