Added tests

src/bin/wasmer.rs

@@ -812,3 +812,14 @@ fn main() {
         }
     }
 }
+
+
+#[test]
+fn filesystem_cache_should_work() -> Result<(), String> {
+    let wasmer_cache_dir = get_cache_dir();
+
+    unsafe {
+        FileSystemCache::new(wasmer_cache_dir).map_err(|e| format!("Cache error: {:?}", e))?
+    };
+    Ok(())
+}