Update http dep to 0.2.7

This is required to use HeaderName::from_static in a const

Cargo.toml

@@ -23,7 +23,7 @@ include = [
 bytes = "1"
 futures-channel = "0.3"
 futures-util = { version = "0.3", default-features = false }
-http = "0.2"
+http = "0.2.7"
 http-body = "=1.0.0-rc.2"
 pin-project-lite = "0.2.4"
 tokio = { version = "1.13", features = ["sync"] }