Update actix-identity requirement from 0.7 to 0.8

Updates the requirements on [actix-identity](https://github.com/actix/actix-extras) to permit the latest version.
- [Release notes](https://github.com/actix/actix-extras/releases)
- [Commits](actix/actix-extras@cors-v0.7.0...session-v0.8.0)

---
updated-dependencies:
- dependency-name: actix-identity
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

juniper_actix/Cargo.toml

@@ -37,7 +37,7 @@ serde_json = "1.0.18"
 
 [dev-dependencies]
 actix-cors = "0.7"
-actix-identity = "0.7"
+actix-identity = "0.8"
 actix-rt = "2.0"
 actix-test = "0.1"
 async-stream = "0.3"