Fix path lookups on Windows

aeron_driver-sys/Cargo.toml

@@ -11,6 +11,7 @@ build = "build.rs"
 [build-dependencies]
 bindgen = "0.51"
 cmake = "0.1"
+dunce = "1.0.0"
 
 [features]
 static = []

aeron_driver-sys/build.rs

@@ -1,7 +1,6 @@
 use cmake::Config;
-
+use dunce::canonicalize;
 use std::env;
-use std::fs::canonicalize;
 use std::path::{Path, PathBuf};
 
 pub enum LinkType {