Streaming media item creation during indexing (#49)

* Implemented streaming during indexing

* Updated file watcher to enqueue download; refactored download worker methods

* Updated File Follower Server timeout

test/pinchflat/utils/filesystem_utils_test.exs

@@ -0,0 +1,16 @@
+defmodule Pinchflat.Utils.FilesystemUtilsTest do
+  use ExUnit.Case, async: true
+
+  alias Pinchflat.Utils.FilesystemUtils
+
+  describe "generate_metadata_tmpfile/1" do
+    test "creates a tmpfile and returns its path" do
+      res = FilesystemUtils.generate_metadata_tmpfile(:json)
+
+      assert String.ends_with?(res, ".json")
+      assert File.exists?(res)
+
+      File.rm!(res)
+    end
+  end
+end