Test the generate method

The `generate` method exists in v17, was deprecated in v18, and removed
in v19.

We have the code already just not the integration test - add it.

Author: tcharding

integration_test/tests/generating.rs

@@ -4,6 +4,16 @@
 
 use integration_test::{Node, NodeExt as _, Wallet};
 
+#[test]
+// The `generate` method deprecated in Core v18 and was removed in v19.
+#[cfg(feature = "v17")]
+fn generate() {
+    const NBLOCKS: usize = 10;
+
+    let node = Node::with_wallet(Wallet::Default, &[]);
+    let _ = node.client.generate(NBLOCKS).expect("generate");
+}
+
 #[test]
 fn generate_to_address() {
     const NBLOCKS: usize = 1;

types/src/v17/mod.rs

@@ -62,7 +62,7 @@
 //!
 //! | JSON-PRC Method Name               | Status          |
 //! |:-----------------------------------|:---------------:|
-//! | generate                           | done (untested) |
+//! | generate                           | done            |
 //! | generatetoaddress                  | done            |
 //!
 //! </details>

types/src/v18/mod.rs

@@ -68,7 +68,7 @@
 //!
 //! | JSON-PRC Method Name               | Status          |
 //! |:-----------------------------------|:---------------:|
-//! | generate                           | done (untested) |
+//! | generate                           | omitted         |
 //! | generatetoaddress                  | done            |
 //!
 //! </details>