added save_chekpoint function

solver.py

@@ -239,8 +239,23 @@ class Solver():
     def save_model(self):
         pass
 
-    def save_checkpoint(self):
-        pass
+    def save_checkpoint(self, state, filename):
+        """General Checkpoint Save
+
+        This function saves a general checkpoint for inference and/or resuming training
+
+        Args:
+            state (dict): Dictionary of all the relevant model components
+
+        Returns:
+            None
+
+        Raises:
+            None
+
+        """
+
+        torch.save(state, filename)
 
     def load_checkpoint(self):
         pass