Fix clippy lint errors

The drawback of using rust-nightly is that time to time new linter rules
are added that render master essentially broken from CI point of view.
This patch fixes existing lint errors.

Author: ikalnytskyi

.github/workflows/tests.yml

@@ -106,7 +106,7 @@ jobs:
       - uses: actions-rs/cargo@v1
         with:
           command: rustdoc
-          args: -- -D intra-doc-link-resolution-failure
+          args: -- -D rustdoc::broken_intra_doc_links
 
   tests:
     runs-on: ubuntu-latest

src/storage/sql/models.rs

@@ -96,10 +96,8 @@ pub fn combine_rows(
                 snippet,
                 changesets_by_snippet_id
                     .remove(&snippet_id)
-                    .unwrap_or_else(Vec::new),
-                tags_by_snippet_id
-                    .remove(&snippet_id)
-                    .unwrap_or_else(Vec::new),
+                    .unwrap_or_default(),
+                tags_by_snippet_id.remove(&snippet_id).unwrap_or_default(),
             ))
         })
         .collect()

src/web/auth.rs

@@ -9,15 +9,15 @@ use serde::Deserialize;
 
 pub use jwt::JwtValidator;
 
-#[derive(Debug, PartialEq, Deserialize)]
+#[derive(Debug, PartialEq, Eq, Deserialize)]
 pub enum Permission {
     /// Allows users to import snippets (i.e. to create new snippets and set
     /// the values of some protected Snippet fields like `id` or `created_at`).
     #[serde(rename(deserialize = "import"))]
     Import,
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum User {
     /// Authenticated user. Can create, retrieve, update, and delete private
     /// snippets. May have additional permissions.