Move all Spotify and LastFM code into only one folder for each

core/agents/spotify/spotify_suite_test.go

@@ -0,0 +1,17 @@
+package spotify
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestSpotify(t *testing.T) {
+	tests.Init(t, false)
+	log.SetLevel(log.LevelCritical)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Spotify Test Suite")
+}