Ensure NDT with ms precision are formatted correctly

Author: Ryan Bigg

lib/aws_auth/utils.ex

@@ -53,6 +53,8 @@ defmodule AWSAuth.Utils do
   def format_time(time) do
     formatted_time = time
     |> NaiveDateTime.to_iso8601
+    |> String.split(".")
+    |> List.first
     |> String.replace("-", "")
     |> String.replace(":", "")
     formatted_time <> "Z"

test/aws_utils_test.exs

@@ -0,0 +1,8 @@
+defmodule AWSAuth.UtilsTest do
+  use ExUnit.Case
+
+  test "format_time formats a time correctly" do
+    time = AWSAuth.Utils.format_time(~N[2016-10-20 10:32:45.12345])
+    assert time == "20161020T103245Z"
+  end
+end