pytest: add notifications to tests.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/plugins/notify.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+
+from pyln.client import Plugin
+import time
+
+plugin = Plugin()
+
+
+@plugin.method("make_notify")
+def make_notify(plugin, request, **kwargs):
+    plugin.notify_message(request, "Beginning stage 1")
+    for i in range(100):
+        plugin.notify_progress(request, i, 100, stage=0, stage_total=2)
+        time.sleep(0.01)
+    plugin.notify_message(request, "Beginning stage 2", level='debug')
+    for i in range(10):
+        plugin.notify_progress(request, i, 10, stage=1, stage_total=2)
+        time.sleep(0.1)
+    return "This worked"
+
+
+plugin.run()