Bump to 0.52.0

Author: ehuss

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cargo"
-version = "0.51.0"
+version = "0.52.0"
 edition = "2018"
 authors = ["Yehuda Katz <wycats@gmail.com>",
            "Carl Lerche <me@carllerche.com>",

tests/testsuite/build.rs

@@ -4330,8 +4330,6 @@ fn target_edition() {
         .build();
 
     p.cargo("build -v")
-        // Passes on nightly, fails on stable, since `--edition` is nightly-only.
-        .without_status()
         .with_stderr_contains(
             "\
 [COMPILING] foo v0.0.1 ([..])