integration: silence warnings about missing docs

Rigorous documentation is not necessary for integration tests.

Author: wprzytula

scylla/tests/integration/main.rs

@@ -1,3 +1,6 @@
+// Rigorous documentation is not necessary for integration tests.
+#![allow(missing_docs)]
+
 pub(crate) mod ccm;
 mod load_balancing;
 mod macros;