Markov chains appear to be training correctly

* Markov chains record words correctly from a single line to the end of
  their line with a couple of exceptions.
* Start working on using ETS for storing markov chains, and saving it as
  a DETS periodically

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

test/contrib/markov/chain_test.exs

@@ -25,7 +25,6 @@ defmodule MarkovChainTest do
     ]
 
     chain = chain |> Chain.add_weight(["foo", "bar"], "qux")
-
     assert chain.chain == [
       {["foo", "bar"], %{"baz" => 3, "qux" => 1}}
     ]