Fix license tag

Tools (like Clearlydefined.io) which automatically try to determine the
license that a component uses understand AND and OR but not "/".

Author: sophokles73

Cargo.toml

@@ -4,7 +4,7 @@ version = "0.4.1"
 authors = ["Herman J. Radtke III <herman@hermanradtke.com>"]
 edition = "2018"
 description = "A connect, read and write timeout aware connector to be used with hyper Client."
-license = "MIT/Apache-2.0"
+license = "MIT OR Apache-2.0"
 documentation = "https://github.com/hjr3/hyper-timeout"
 homepage = "https://github.com/hjr3/hyper-timeout"
 repository = "https://github.com/hjr3/hyper-timeout"