fix: Resolve beta-build warnings

Fine line to walk, making beta/nightly happy with the warning but making
stable happy where the warning doesn't exist.

Author: epage

src/bin/cobalt/main.rs

@@ -1,5 +1,7 @@
 // Deny warnings, except in dev mode
 #![deny(warnings)]
+#![allow(unknown_lints)]
+#![allow(unused_doc_comment)] // error-chain 0.11 should fix this.
 #![cfg_attr(feature="dev", warn(warnings))]
 
 // stuff we want clippy to ignore

src/cobalt.rs

@@ -152,7 +152,7 @@ pub fn build(config: &Config) -> Result<()> {
         .collect();
 
     trace!("Generating posts");
-    for (i, mut post) in &mut posts.iter_mut().enumerate() {
+    for (i, post) in &mut posts.iter_mut().enumerate() {
         trace!("Generating {}", post.url_path);
 
         // posts are in reverse date order, so previous post is the next in the list (+1)

src/lib.rs

@@ -1,6 +1,7 @@
 // Deny warnings, except in dev mode
 #![deny(warnings)]
-// #![deny(missing_docs)]
+#![allow(unknown_lints)]
+#![allow(unused_doc_comment)] // error-chain 0.11 should fix this.
 #![cfg_attr(feature="dev", warn(warnings))]
 
 // Stuff we want clippy to ignore