Bump tokio to 0.2.13

Summary:
This is needed because the tonic crate (see the diff stack) relies on tokio ^0.2.13

We can't go to a newer version because a bug that affects mononoke was introduced on 0.2.14 (discussion started on T65261126). The issue was reported upstream tokio-rs/tokio#2390

This diff simply changed the version number on `fbsource/third-party/rust/Cargo.toml` and ran `fbsource/third-party/rust/reindeer/vendor`.

Also ran `buck run //common/rust/cargo_from_buck:cargo_from_buck` to fix the tokio version on generated cargo files

Reviewed By: krallin

Differential Revision: D21043344

fbshipit-source-id: e61797317a581aa87a8a54e9e2ae22655f22fb97

resctl/below/Cargo.toml

@@ -36,6 +36,6 @@ slog-async = "2.3"
 slog-term = "2.4.2"
 structopt = "0.3.7"
 tempdir = "0.3"
-tokio = { version = "=0.2.11", features = ["full"] }
+tokio = { version = "=0.2.13", features = ["full"] }
 toml = "=0.5.5"
 walkdir = "2.2.9"