fix get_current_execution (#23)

* fix get_current_execution

* fix return type

Author: vlebourl

tahoma_api/client.py

@@ -118,12 +118,12 @@ async def fetch_event_listener(self, listener_id: str) -> List[Event]:
 
         return events
 
-    async def get_current_execution(self, exec_id: str) -> List[Execution]:
+    async def get_current_execution(self, exec_id: str) -> Execution:
         """ Get an action group execution currently running """
         response = await self.__get(f"exec/current/{exec_id}")
-        executions = [Execution(**e) for e in humps.decamelize(response)]
+        execution = Execution(**humps.decamelize(response))
 
-        return executions
+        return execution
 
     async def get_current_executions(self) -> List[Execution]:
         """ Get all action groups executions currently running """