remove idiom lints

Author: steveklabnik

_posts/2018-10-29-help-test-rust-2018.md

@@ -113,24 +113,4 @@ edition = "2018"
 ```
 
 See that `edition = "2018"`? That's what opts you in to the new features.
-Set it, `cargo +beta build`, and you should be good to go!
-
-## Writing idiomatic code
-
-We have some new lints that suggest using certain idioms in your Rust 2018
-code. We don't have them turned on by default yet. To see what your code would
-look like, you can use `cargo fix`:
-
-```console
-$ cargo +beta fix --edition-idioms
-```
-
-If things look great, or things look terrible, please let us know! We hope to make
-these lints warn by default after gaining some experience with them and working
-out the bugs.
-
-> The `--edition-idioms` flag applies only to the "current crate"; if you want
-> to run it against a workspace is necessary to use a workaround with `RUSTFLAGS`
-> in order to execute it in all the workspace members.
-> 
->     $ RUSTFLAGS='-Wrust_2018_idioms' cargo fix --all
+Set it, `cargo +beta build`, and you should be good to go!