Resolve clap deprecations

    warning: use of deprecated variant `clap::AppSettings::DontCollapseArgsInUsage`: Replaced with `Command::dont_collapse_args_in_usage` and `Command::is_dont_collapse_args_in_usage_set`
      --> src/opts.rs:16:32
       |
    16 |         setting = AppSettings::DontCollapseArgsInUsage
       |                                ^^^^^^^^^^^^^^^^^^^^^^^

    warning: use of deprecated associated function `clap::CommandFactory::into_app`: Replaced with `CommandFactory::command
       --> src/opts.rs:168:30
        |
    168 |     <Opts as clap::IntoApp>::into_app().debug_assert();
        |                              ^^^^^^^^

src/opts.rs

@@ -13,7 +13,7 @@ pub enum Opts {
         version,
         author,
         setting = AppSettings::DeriveDisplayOrder,
-        setting = AppSettings::DontCollapseArgsInUsage
+        dont_collapse_args_in_usage = true
     )]
     Expand(Args),
 }
@@ -165,5 +165,5 @@ fn parse_selector(s: &str) -> Result<Selector, <Selector as FromStr>::Err> {
 
 #[test]
 fn test_cli() {
-    <Opts as clap::IntoApp>::into_app().debug_assert();
+    <Opts as clap::CommandFactory>::command().debug_assert();
 }