deps: deadpool @ 0.7

Might as well upgrade before the connection pooling PR goes out.

Author: Fishrock123

Cargo.toml

@@ -39,7 +39,7 @@ log = "0.4.7"
 async-h1 = { version = "2.0.0", optional = true }
 async-std = { version = "1.6.0", default-features = false, optional = true }
 async-native-tls = { version = "0.3.1", optional = true }
-deadpool = { version = "0.6.0", optional = true }
+deadpool = { version = "0.7.0", optional = true }
 futures = { version = "0.3.8", optional = true }
 
 # h1_client_rustls