Add a "ci" feature to make clippy ignore docs warnings

plume-models/Cargo.toml

@@ -54,3 +54,4 @@ diesel_migrations = "1.3.0"
 [features]
 postgres = ["diesel/postgres", "plume-macro/postgres" ]
 sqlite = ["diesel/sqlite", "plume-macro/sqlite" ]
+ci = ["plume-macro/ci"]

plume-models/src/lib.rs

@@ -1,7 +1,7 @@
 #![feature(try_trait)]
 #![feature(never_type)]
 #![feature(proc_macro_hygiene)]
-#![warn(missing_docs)]
+#![cfg_attr(not(feature = "ci"), warn(missing_docs))]
 
 #[macro_use]
 extern crate diesel;