Add clearml logging (#51)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

ultralytics/yolo/utils/callbacks/base.py

@@ -0,0 +1,41 @@
+def before_train(trainer):
+    # Initialize tensorboard logger
+    pass
+
+
+def on_epoch_start(trainer):
+    pass
+
+
+def on_batch_start(trainer):
+    pass
+
+
+def on_val_start(trainer):
+    pass
+
+
+def on_val_end(trainer):
+    pass
+
+
+def on_model_save(trainer):
+    pass
+
+
+default_callbacks = {
+    "before_train": before_train,
+    "on_epoch_start": on_epoch_start,
+    "on_batch_start": on_batch_start,
+    "on_val_start": on_val_start,
+    "on_val_end": on_val_end,
+    "on_model_save": on_model_save}
+
+
+def add_integration_callbacks(trainer):
+    callbacks = {}
+
+    from .clearml import callbacks, clearml
+    if clearml:
+        for callback, func in callbacks.items():
+            trainer.add_callback(callback, func)