feat: add runtime-tokio feature (#92)

Add a `runtime-tokio` feature that does not select a tls impl. This is useful
when using sqlx-adapter via a UDS backed pool.

Signed-off-by: Joe Grund <[email protected]>

Author: Joe Grund

Cargo.toml

@@ -29,6 +29,7 @@ sqlite = ["sqlx/sqlite"]
 runtime-async-std-native-tls = ["casbin/runtime-async-std", "sqlx/runtime-async-std-native-tls"]
 runtime-async-std-rustls = ["casbin/runtime-async-std", "sqlx/runtime-async-std-rustls"]
 # tokio
+runtime-tokio = ["casbin/runtime-tokio", "sqlx/runtime-tokio"]
 runtime-tokio-native-tls = ["casbin/runtime-tokio", "sqlx/runtime-tokio-native-tls"]
 runtime-tokio-rustls = ["casbin/runtime-tokio", "sqlx/runtime-tokio-rustls"]