ci: deny multiple allow-by-default lints (#22)

* ci: deny multiple allow-by-default lints

* chore: add a changelog

* fix: wrong indentation

* ci: allow `single_use_lifetimes`

It doesn't work. See: rust-lang/rust#53738 (comment)

.github/workflows/rust.yml

@@ -4,7 +4,7 @@ on: [push, pull_request]
 
 env:
   CARGO_TERM_COLOR: always
-  RUSTFLAGS: -D warnings -D rustdoc -D missing_docs
+  RUSTFLAGS: -D warnings -D absolute_paths_not_starting_with_crate -D disjoint_capture_drop_reorder -D elided_lifetimes_in_paths -D explicit_outlives_requirements -D macro_use_extern_crate -D meta_variable_misuse -D missing_abi -D missing_copy_implementations -D missing_debug_implementations -D non_ascii_idents -D pointer_structural_match -D semicolon_in_expressions_from_macros -D trivial_casts -D trivial_numeric_casts -D unaligned_references -D unreachable_pub -D unused_extern_crates -D unused_import_braces -D unused_lifetimes -D unused_qualifications -D rustdoc -D missing_docs
 
 jobs:
   build:

CHANGELOG.md

@@ -4,6 +4,7 @@
 ### Changed
 - Bors is no longer used for merging PRs ([#20](https://github.com/toku-sa-n/accessor/pull/20)).
 - Tests on CI are executed on stable Rust, not the nightly one ([#21](https://github.com/toku-sa-n/accessor/pull/21)).
+- Multiple lints that are allowed by default are now denied ([#22](https://github.com/toku-sa-n/accessor/pull/22)).
 - `rustfmt.toml` is deleted so that `cargo fmt` works on stable Rust ([#23](https://github.com/toku-sa-n/accessor/pull/23)).
 
 ### Fixed