some cleaning after merged ws2pheads

lib/ws2p_heads/server_conf.ex

-defmodule Server.Conf.Keypair do
-
-  use GenServer
-  def init(_init) do
-    #TODO: read keypair from .yml file
-    seckey = "2DLT4zDuuQSsEehijzkwCwdvH4vrsp6joBf4rum9Zb8jDTBKhDfZawSYsGeWy56cPDUGbWf5ybJgADNnVcnJ3sek"
-    pubkey = "BhQf2fkGAe1EszyZRJqasMr23YLSf1P3mhuYzEoKpgVA"
-    {:ok, {pubkey, seckey}}
-  end
-
-  def start_link() do
-    GenServer.start_link(__MODULE__, [],name: {:via, Registry, {WS2P.HeadCache.Registry, :keypair}})
-  end
-
-  def handle_call({:get_pubkey}, _from, state) do
-    {pubkey, _} = state
-    {:reply, pubkey, state}
-  end
-
-  def handle_call({:get_seckey}, _from, state) do
-    {pubkey, _} = state
-    {:reply, pubkey, state}
-  end
-
-end
-
-defmodule Server.Conf.WS2PID do
-  use GenServer
-  #TODO: generate ws2pid when we synchronize a node, then put ws2p id into db
-  def init(_init) do
-    #TODO: read ws2pid from db
-    ws2pid = UUID.uuid4() |> String.split("-") |> List.first()
-    {:ok, ws2pid}
-  end
-
-  def start_link() do
-    GenServer.start_link(__MODULE__, [],name: {:via, Registry, {WS2P.HeadCache.Registry, :ws2pid}})
-  end
-
-  def handle_call({:get_ws2pid}, _from, ws2pid) do
-    {:reply, ws2pid, ws2pid}
-  end
-
-end

lib/ws2p_heads/ws2p_headscache.ex

-defmodule WS2P.HeadsCache do
-  use GenServer
-  require Logger
-
-  def init(_args) do
-    {:ok, %{}}
-  end
-
-  @spec start_link(any) :: :ignore | {:error, any} | {:ok, pid}
-  def start_link(_args) do
-    GenServer.start_link(__MODULE__, [],
-      name: {:via, Registry, {WS2P.HeadCache.Registry, :headcache}}
-    )
-  end
-
-  def handle_call(:get_headcache, _from, state) do
-    {:reply, state, state}
-  end
-
-  def handle_cast({:update_headcache, new_heads_cache}, _old_heads_cache) do
-    {:noreply, new_heads_cache}
-  end
-end