feat: bump version to 2.8.0

Author: hsluoyz

Diff for: Cargo.toml

@@ -8,7 +8,7 @@ license = "Apache-2.0"
 name = "casbin"
 readme = "README.md"
 repository = "https://github.com/casbin/casbin-rs"
-version = "2.7.0"
+version = "2.8.0"
 
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

Diff for: README.md

@@ -36,7 +36,7 @@ Add this package to `Cargo.toml` of your project. (Check https://crates.io/crate
 
 ```toml
 [dependencies]
-casbin = { version = "2.7.0", default-features = false, features = ["runtime-async-std", "logging", "incremental"] }
+casbin = { version = "2.8.0", default-features = false, features = ["runtime-async-std", "logging", "incremental"] }
 tokio = { version = "1.10.0", features = ["fs", "io-util"] }
 ```