ci: Add rust image

.drone.yml

@@ -4,13 +4,14 @@ workspace:
 
 pipeline:
     release:
-        image: rust:latest
+        image: rust:1.32
         commands:
           - cargo build --release
         when:
             event: tag
 
     test:
+        image: rust:1.32
         commands:
           - cargo test
         when: