adds simple in memory config manager

vocode/streaming/telephony/config_manager/in_memory_config_manager.py

@@ -0,0 +1,19 @@
+from typing import Optional
+from vocode.streaming.models.telephony import CallConfig
+from vocode.streaming.telephony.config_manager.base_config_manager import (
+    BaseConfigManager,
+)
+
+
+class InMemoryConfigManager(BaseConfigManager):
+    def __init__(self):
+        self.configs = {}
+
+    def save_config(self, conversation_id: str, config: CallConfig):
+        self.configs[conversation_id] = config
+
+    def get_config(self, conversation_id) -> Optional[CallConfig]:
+        return self.configs.get(conversation_id)
+
+    def delete_config(self, conversation_id):
+        del self.configs[conversation_id]