update vm-superio dep for vm-superio-ser v0.1.0

vm-superio v0.5.0 is published on crates.io. We have to update
this dependency for vm-superio-ser in order to be able to publish
that crate as well.

Signed-off-by: Laura Loghin <[email protected]>

crates/vm-superio-ser/Cargo.toml

@@ -13,4 +13,10 @@ edition = "2018"
 serde = { version = ">=1.0.27", features = ["derive"] }
 versionize = ">=0.1.6"
 versionize_derive = ">=0.1.3"
-vm-superio = { path =  "../vm-superio" }
+# Combining both `version` and `path` so that it is possible to publish
+# the crate on crates.io. More details here:
+# https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#multiple-locations.
+# We are using a fixed version of `vm-superio` so that the current version
+# of `vm-superio-ser` won't take a newer version of vm-superio, with which
+# it may not be compatible.
+vm-superio = { version = "=0.5.0", path = "../vm-superio" }