scanner: Add a base class for queued Tasks

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

scanner/__init__.py

@@ -1,2 +1,3 @@
 # Copyright 2021 (c) Anna Schumaker.
 from . import metadata
+from . import task

scanner/task.py

@@ -0,0 +1,5 @@
+# Copyright 2021 (c) Anna Schumaker.
+from gi.repository import GObject
+
+class Task(GObject.GObject):
+    def run_task(self): raise NotImplementedError

scanner/test_task.py

@@ -0,0 +1,11 @@
+# Copyright 2021 (c) Anna Schumaker.
+import unittest
+from gi.repository import GObject
+from . import task
+
+class TestScannerTask(unittest.TestCase):
+    def test_scanner_task_init(self):
+        t = task.Task()
+        self.assertIsInstance(t, GObject.GObject)
+        with self.assertRaises(NotImplementedError):
+            t.run_task()