Problem
A Domain Name Server converts site names, like google.com, to their IP address 172.217.3.174. Using a dictionary is faster than a list, because you do not need to check other elements to find the right one.
I. Write a fake_create_initial_network_dict function, that creates a dict with three items, make the server name be the key (i.e. google.com), and the server ip be the value (i.e. 172.217.3.174)
II. Write a fake_add_to_network function, that takes a network dictionary, a server name, and an ip, and adds the new IP to the list.
III. Write a fake_dns_lookup function, that takes a network dict and a server name, and returns the IP. Return "Not found" if name doesn't exist.