Use bigint for version and aggregate_version fields in the DB (#32)

priv/chronik_repo/migrations/20180118142813_bigint_for_version.exs

@@ -0,0 +1,14 @@
+defmodule Chronik.Store.Adapters.Ecto.ChronikRepo.Migrations.BigintForVersion do
+  use Ecto.Migration
+
+  def change do
+    alter table(:aggregates) do
+      modify :snapshot_version, :bigint
+    end
+
+    alter table(:domain_events) do
+      modify :aggregate_version, :bigint
+      modify :version, :bigint
+    end
+  end
+end