auto/terraform: typing hints for base terraform module

app/terraform/__init__.py

@@ -1,10 +1,11 @@
+from abc import ABCMeta, abstractmethod
 import os
 from typing import Tuple
 
 from app import app
 
 
-class BaseAutomation:
+class BaseAutomation(metaclass=ABCMeta):
     short_name: str = "base"
     description: str = "Abstract base automation."
     frequency: int
@@ -14,6 +15,7 @@ class BaseAutomation:
     the portal system.
     """
 
+    @abstractmethod
     def automate(self, full: bool = False) -> Tuple[bool, str]:
         raise NotImplementedError()