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/valueFrom_test.go

@@ -0,0 +1,25 @@
+package labelstructs
+
+import (
+	"testing"
+)
+
+func TestValueFromLabel(t *testing.T) {
+	data := "data: foo\ndata2: bar"
+	tc, err := GetValueFrom(data)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if tc == nil {
+		t.Fatalf("expected non-nil map, got nil")
+	}
+	if len(*tc) != 2 {
+		t.Errorf("expected 2 items, got %d", len(*tc))
+	}
+	if (*tc)["data"] != "foo" {
+		t.Errorf("expected 'data' to be 'foo', got %s", (*tc)["data"])
+	}
+	if (*tc)["data2"] != "bar" {
+		t.Errorf("expected 'data2' to be 'bar', got %s", (*tc)["data2"])
+	}
+}