You're going to start creating a server that implements a stack. The call that initializes your stack will pass in a list of the initial stack contents.
For now, implement only the pop interface. It's acceptable for your server to crash if someone tries to pop from an empty stack.
For example, if initialized with [5,"cat",9], successive calls to pop will return 5, "cat", and 9
See the stack directory for the full project.
iex> {:ok, pid} = GenServer.start_link(Stack.Server, [5,"cat",9])
{:ok, #PID<0.125.0>}
iex> GenServer.call(pid, :pop)
5
iex> GenServer.call(pid, :pop)
"cat"
iex> GenServer.call(pid, :pop)
9