join: switch to auto-generated main.rs

src/join/Cargo.toml

@@ -2,6 +2,7 @@
 name = "join"
 version = "0.0.1"
 authors = []
+build = "../../mkmain.rs"
 
 [lib]
 name = "uu_join"
@@ -13,4 +14,4 @@ uucore = { path="../uucore" }
 
 [[bin]]
 name = "join"
-path = "main.rs"
+path = "../../uumain.rs"

src/join/main.rs

@@ -1,5 +0,0 @@
-extern crate uu_join;
-
-fn main() {
-    std::process::exit(uu_join::uumain(std::env::args().collect()));
-}