make tests async

test/auto_linker_test.exs

 defmodule AutoLinkerTest do
-  use ExUnit.Case
+  use ExUnit.Case, async: true
   doctest AutoLinker
 
   test "phone number" do

test/builder_test.exs

 defmodule AutoLinker.BuilderTest do
-  use ExUnit.Case
+  use ExUnit.Case, async: true
   doctest AutoLinker.Builder
 
   import AutoLinker.Builder

test/parser_test.exs

 defmodule AutoLinker.ParserTest do
-  use ExUnit.Case
+  use ExUnit.Case, async: true
   doctest AutoLinker.Parser
 
   import AutoLinker.Parser
@@ -68,7 +68,7 @@ defmodule AutoLinker.ParserTest do
 
     test "excludes html with specified class" do
       text = "```Check out <div class='section'>google.com</div>```"
-      assert parse(text, exclude_pattern: "```") == text
+      assert parse(text, exclude_patterns: ["```"]) == text
     end
   end