add before_run (#4)

swankit/callback/__init__.py

@@ -11,6 +11,7 @@
 from typing import Callable
 from abc import ABC, abstractmethod
 from .models import *
+from swankit.core import SwanLabSharedSettings
 
 
 class SwanKitCallback(ABC):
@@ -29,6 +30,13 @@ def on_init(self, proj_name: str, workspace: str, logdir: str = None, **kwargs):
         """
         pass
 
+    def before_run(self, settings: SwanLabSharedSettings):
+        """
+        在运行实验之前调用
+        :param settings: SwanLabSharedSettings, 运行时的共享配置
+        """
+        pass
+
     def before_init_experiment(
             self,
             run_id: str,