Added print to show epoch number

This can be used to identify if the data set is in fact repeated.
In that case this print line has to be printed at least twice.

Signed-off-by: Jim Martens <github@2martens.de>

src/twomartens/masterthesis/ssd.py

@@ -465,6 +465,10 @@ def _train_epochs(nr_batches_per_epoch: int,
                 # epoch starts
                 epoch_start_time = time.time()
                 ssd_loss_avg = tfe.metrics.Mean(name='ssd_loss', dtype=tf.float32)
+                if verbose:
+                    print((
+                        f"epoch: {epoch + 1:d}"
+                    ))
             
             labels = []
             for i in range(y.shape[0]):