feat: include Synapse into integration test

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

integration_test/users.dart

@@ -0,0 +1,16 @@
+abstract class Users {
+  const Users._();
+  static const alice = User('alice', 'AliceInWonderland');
+  static const bob = User('bob', 'JoWirSchaffenDas');
+  static const trudy = User('trudy', 'HaveIBeenPwned');
+}
+
+class User {
+  final String name;
+  final String password;
+
+  const User(this.name, this.password);
+}
+
+// https://stackoverflow.com/a/33088657
+const homeserver = 'http://10.0.2.2:8008';