Update integration tests

Author: khvzak

tests/tests.rs

@@ -5,14 +5,20 @@ fn test_build() {
     let host = target_lexicon::Triple::host().to_string();
     let outdir = tempfile::tempdir().expect("Failed to create temp dir");
     let mut build = lua_src::Build::new();
-    build.target(&host).out_dir(&outdir);
+    build.target(&host);
 
     for version in [
         lua_src::Lua51,
         lua_src::Lua52,
         lua_src::Lua53,
         lua_src::Lua54,
+        lua_src::Lua55,
     ] {
+        // Use a dedicated output dir for each Lua version
+        let version_dir = outdir.path().join(format!("{:?}", version));
+        std::fs::create_dir(&version_dir).expect("Failed to create version dir");
+
+        build.out_dir(&version_dir);
         let _artifacts = build.build(version);
     }
 }