Add test fixture.

test/publishing/TestPdfWriter.cpp

@@ -3,7 +3,9 @@
 #include "PdfObject.h"
 #include "File.h"
 
-int main()
+#include "TestFramework.h"
+
+TEST_CASE(TestPdfWriter, "publishing")
 {
     auto document = std::make_unique<PdfDocument>();
 
@@ -14,5 +16,4 @@ int main()
     pdf_file.SetAccessMode(File::AccessMode::Write);
     pdf_file.Open();
     pdf_file.WriteText(output);
-    return 0;
 }