Fix failing test for searching by tag

This test has been proving that if a tag matches a note that it will
gather the note linked to the tag vertex, but we have also introduced
gathering the context line number, which the test isn't stubbing a
test scenario that will match context.

Ignore for now.

notebook/notebook_test.go

@@ -18,7 +18,7 @@ func TestSearchByTag(t *testing.T) {
 	book := &Notebook{Notes: g}
 
 	got := book.SearchByTags("#foo")
-	want := []Result{{Value: graph.Vertex{Id: 2, Label: "note"}}}
+	want := []Result{{Line: -1, Value: graph.Vertex{Id: 2, Label: "note"}}}
 
 	if !reflect.DeepEqual(got, want) {
 		t.Fatalf("Expected: %+v\nGot: %+v", want, got)