Update minimal version of pin-project-lite to 0.2.12 (#66)

Author: taiki-e

strategy/Cargo.toml

@@ -13,7 +13,7 @@ exclude = ["/.*"]
 
 [dependencies]
 event-listener = { path = "..", version = "2", default-features = false }
-pin-project-lite = "0.2.9"
+pin-project-lite = "0.2.12"
 
 [features]
 default = ["std"]