add test report generation

Author: reschke

src/test/java/org/greenbytes/http/sfv/AbstractSpecificationTests.java

@@ -229,7 +229,7 @@ public void executeTest(StringBuilder out) {
                 fail("should fail, but passed. Input >>>" + p.raw + "<<<, Output >>>" + parsed.serialize() + "<<<");
             } catch (ParseException expected) {
                 out.append("~~~\n");
-                out.append(expected.getDiagnostics()).append("\n");
+                out.append(expected.getDiagnostics());
                 out.append("~~~\n");
                 out.append("\n");
             }

src/test/java/org/greenbytes/http/sfv/SpecificationTests.java

@@ -44,14 +44,18 @@ public SpecificationTests(Object x, Object y) {
     @Test
     public void runTest() {
         StringBuilder out = new StringBuilder();
+        if (basename.isEmpty()) {
+            out.append("# Test Report\n");
+            out.append("\n");
+        }
         if (!p.filename.equals(basename)) {
             out.append("\n");
-            out.append("# ").append(p.filename).append("\n");
+            out.append("## ").append(p.filename).append("\n");
             out.append("\n");
             basename = p.filename;
             out.append("\n");
         }
-        out.append("## ").append(p.name).append("\n");
+        out.append("### ").append(p.name).append("\n");
         out.append("\n");
         out.append("Input:").append("\n");
         out.append("~~~" + "\n");