Add binary search to Util

For some reason there doesn't appear to be a binary search function in
Elixir's standard library, so this implements that.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

lib/contrib/markov/markov.ex

@@ -0,0 +1,22 @@
+defmodule Omnibot.Contrib.Markov do
+  use Omnibot.Plugin
+
+  alias Omnibot.Contrib.Markov.Chain
+
+  @default_config path: :"wordbot.ets", order: 2
+
+  @impl true
+  def on_init(cfg) do
+    # Create the markov database
+    path = if is_atom(cfg[:path]),
+      do: cfg[:path],
+      else: String.to_atom(cfg[:path])
+    {:ok, db} = :dets.open_file(path)
+    db
+  end
+
+  @impl true
+  def on_channel_msg(_irc, _channel, _nick, msg) do
+    _words = String.split(msg, ~r/\s+/)
+  end
+end