updated slab (fixes out-of-bound access in get_disjoint_mut) (#171)

https://github.com/tokio-rs/slab/pull/152

Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "addr2line"
@@ -748,12 +748,9 @@ dependencies = [
 
 [[package]]
 name = "slab"
-version = "0.4.8"
+version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6528351c9bc8ab22353f9d776db39a20288e8d6c37ef8cfe3317cf875eecfc2d"
-dependencies = [
- "autocfg",
-]
+checksum = "7a2ae44ef20feb57a68b23d846850f861394c2e02dc425a50098ae8c90267589"
 
 [[package]]
 name = "smallvec"