Auto merge of #254 - dsherret:chore_bump_parking_lot, r=jdm

fix: bump parking_lot to 0.12 in order to not create wasm export

parking_lot 0.11 was using parking_lot_core 0.8 which was creating a wasm export when targeting wasm: Amanieu/parking_lot#269

This bumps to parking_lot 0.12, which uses parking_lot_core 0.9 which doesn't have the issue where it creates the wasm export.

Cargo.toml

@@ -27,7 +27,7 @@ lazy_static = "1.1.0"
 serde = { version = "1", optional = true }
 phf_shared = "0.10"
 new_debug_unreachable = "1.0.2"
-parking_lot = "0.11"
+parking_lot = "0.12"
 
 [[test]]
 name = "small-stack"