[WIP] Monkeypatch tests (#448)

* Parameterize test_internals.py

* Create test_spotify_tools.py

* Monkeypatch pafy.download

* Monkeypatch YouTube search page

* Replace globals with fixtures

* Add missing urllib import, re-ordering and rename test_with_metadata.py

* Avoid creating temp directory in current working directory during test

* Update CHANGES.md

spotdl/downloader.py

@@ -1,3 +1,8 @@
+import spotipy
+import urllib
+import os
+from logzero import logger as log
+
 from spotdl import const
 from spotdl import metadata
 from spotdl import convert
@@ -5,10 +10,6 @@ from spotdl import internals
 from spotdl import spotify_tools
 from spotdl import youtube_tools
 
-import spotipy
-from logzero import logger as log
-import os
-
 
 class CheckExists:
     def __init__(self, music_file, meta_tags=None):