message: enable cargo edition feature & bump to 2018
diff: @@ -1025,10 +1025,13 @@ fn installs_from_cwd_with_2018_warnings() {
  .file(
  "Cargo.toml",
  r#"
  + cargo-features = ["edition"]
  +
  [package]
  name = "foo"
  version = "0.1.0"
  authors = []
  + rust = "2018"
  "#,
  )
  .file("src/main.rs", "fn main() {}")
  