Increase coverage (#218)

* Monkeypatch fetch user and use pytest.tempdir

* Cover spotify_tools.grab_album()

* Cover avconv conversion

* Cover grab_single()

* Reduce code repetition

* Move grab_playlist() to spotify_tools.py

* Move Spotify specific functions to spotify_tools.py

* Refactoring

* Return track list from write_tracks()

* Fix tests

* Cover more cases in generate_youtube_url()

* Test for unavailable audio streams

* Test for filename without spaces

* handle.py 100% coverage

* Improve config tests

* Speed up tests

* Install avconv and libfdk-aac

* Some cleaning

* FFmpeg with libfdk-aac, libopus

* Some refactoring

* Convert tmpdir to string

* Cover YouTube title when downloading from list

* Explicitly cover some internals.py functions

test/test_handle.py

@@ -0,0 +1,34 @@
+from core import handle
+
+import pytest
+import os
+import sys
+
+
+def test_log_str_to_int():
+    expect_levels = [20, 30, 40, 10]
+    levels = [handle.log_leveller(level)
+              for level in handle._LOG_LEVELS_STR]
+    assert levels == expect_levels
+
+
+class TestConfig:
+    def test_default_config(self, tmpdir):
+        expect_config = handle.default_conf['spotify-downloader']
+        global config_path
+        config_path = os.path.join(str(tmpdir), 'config.yml')
+        config = handle.get_config(config_path)
+        assert config == expect_config
+
+    def test_modified_config(self):
+        default_config = handle.default_conf['spotify-downloader']
+        modified_config = dict(default_config)
+        modified_config['file-format'] = 'just_a_test'
+        config = handle.merge(default_config, modified_config)
+        assert config['file-format'] == modified_config['file-format']
+
+
+def test_grouped_arguments(tmpdir):
+    sys.path[0] = str(tmpdir)
+    with pytest.raises(SystemExit):
+        handle.get_arguments(to_group=True, to_merge=True)