feat(refacto): move everything in internal package

This allows to install katenary with `go install` and to clean up the
project folder.

internal/generator/labels/labelstructs/exchangeVolume_test.go

@@ -0,0 +1,17 @@
+package labelstructs
+
+import "testing"
+
+func TestExchangeVolumeLabel(t *testing.T) {
+	ts := "- name: exchange-volume\n  mountPath: /exchange\n  readOnly: true"
+	tc, _ := NewExchangeVolumes(ts)
+	if len(tc) != 1 {
+		t.Errorf("Expected ExchangeVolumeLabel to have 1 item, got %d", len(tc))
+	}
+	if tc[0].Name != "exchange-volume" {
+		t.Errorf("Expected ExchangeVolumeLabel to contain 'exchange-volume', got %s", tc[0].Name)
+	}
+	if tc[0].MountPath != "/exchange" {
+		t.Errorf("Expected MountPath to be '/exchange', got %s", tc[0].MountPath)
+	}
+}