Merge pull request #983 from rust-lang/dependabot/cargo/tokio-0.2.23

Cargo.lock

@@ -1768,9 +1768,9 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tokio"
-version = "0.2.22"
+version = "0.2.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d34ca54d84bf2b5b4d7d31e901a8464f7b60ac145a284fba25ceb801f2ddccd"
+checksum = "a6d7ad61edd59bfcc7e80dababf0f4aed2e6d5e0ba1659356ae889752dfc12ff"
 dependencies = [
  "bytes",
  "fnv",