Merge branch 'master' into ab-fix-failed_created_addresses-process

apps/explorer/priv/repo/migrations/20190228102650_add_index_created_contract_address_hash.exs

@@ -0,0 +1,7 @@
+defmodule Explorer.Repo.Migrations.AddIndexCreatedContractAddressHas do
+  use Ecto.Migration
+
+  def change do
+    create(index(:transactions, [:created_contract_address_hash]))
+  end
+end