[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/spotdl.py

@@ -1,5 +1,11 @@
 #!/usr/bin/env python3
 
+import sys
+import platform
+import pprint
+import logzero
+from logzero import logger as log
+
 from spotdl import __version__
 from spotdl import const
 from spotdl import handle
@@ -7,11 +13,6 @@ from spotdl import internals
 from spotdl import spotify_tools
 from spotdl import youtube_tools
 from spotdl import downloader
-from logzero import logger as log
-import logzero
-import sys
-import platform
-import pprint
 
 
 def debug_sys_info():