feat: include Synapse into integration test

Signed-off-by: TheOneWithTheBraid <the-one@with-the-braid.cf>

integration_test/synapse/data/localhost.log.config

@@ -0,0 +1,27 @@
+version: 1
+
+formatters:
+  precise:
+    format: '%(asctime)s - %(name)s - %(lineno)d - %(levelname)s - %(request)s - %(message)s'
+
+handlers:
+
+
+  console:
+    class: logging.StreamHandler
+    formatter: precise
+
+loggers:
+    synapse.storage.SQL:
+        # beware: increasing this to DEBUG will make synapse log sensitive
+        # information such as access tokens.
+        level: INFO
+
+root:
+    level: INFO
+
+
+    handlers: [console]
+
+
+disable_existing_loggers: false

integration_test/synapse/data/localhost.signing.key

@@ -0,0 +1 @@
+ed25519 a_SLrz 0Ho/81rZZve88zdRxhaXWHUT6K3OqzmP35rNMZBUr6I