use crate tempfile for test

.travis.yml

@@ -3,4 +3,4 @@ rust:
   - nightly
 script:
   - cargo build
-  - cargo test --verbose -- --test-threads=1
+  - cargo test --verbose

rcore-fs/Cargo.toml

@@ -14,5 +14,8 @@ bit-vec = { default-features = false, git = "https://github.com/AltSysrq/bit-vec
 static_assertions = "0.3"
 spin = "0.4"
 
+[dev-dependencies]
+tempfile = "3"
+
 [features]
 std = []

rcore-fs/src/tests.rs

@@ -16,8 +16,7 @@ fn _open_sample_file() -> Arc<SimpleFileSystem> {
 }
 
 fn _create_new_sfs() -> Arc<SimpleFileSystem> {
-    let file = OpenOptions::new()
-        .read(true).write(true).create(true).open("test.img")
+    let file = tempfile::tempfile()
         .expect("failed to create file");
     SimpleFileSystem::create(Box::new(file), 32 * 4096)
 }