rewrite blockchain/current test with last block

test/http/blockchain/current_test.exs

@@ -4,14 +4,13 @@ defmodule HTTP.Blockchain.CurrentTest do
   """
   use ExUnit.Case
 
-  # last block in our case is the 50th
-  @last_blcok '49'
-  @base_url 'https://g1-test.duniter.org/blockchain/block/' ++ @last_blcok
+  @base_url 'https://g1-test.duniter.org/blockchain/block/'
 
   @base_url_localhost 'http://localhost:8085/blockchain/current'
 
   test "HTTP Blockchain/current get test" do
-    {:ok, {_, _, res_baseline}} = :httpc.request(:get, {@base_url, []}, [], [])
+    last_block = DB.size('block') - 1
+    {:ok, {_, _, res_baseline}} = :httpc.request(:get, {@base_url ++ to_charlist(last_block), []}, [], [])
     {:ok, {_, _, res}} = :httpc.request(:get, {@base_url_localhost, []}, [], [])
     assert Poison.decode!(res) == Poison.decode!(res_baseline)
   end