Replace tempdir with tempfile

Cargo.toml

@@ -14,4 +14,4 @@ tokio = { version = "1.6.1", features = ["rt", "process", "io-util", "macros", "
 once_cell = "1.4"
 
 [dev-dependencies]
-tempdir = "0.3"
+tempfile = "3"

tests/file.rs

@@ -4,10 +4,10 @@ use schematics::symbols::Symbol;
 use std::fs::File;
 use std::io::Write;
 use std::path::{Path, PathBuf};
-use tempdir::TempDir;
+use tempfile::{tempdir, TempDir};
 
 fn get_dir(content: Option<&str>) -> TempDir {
-  let tmp_dir = TempDir::new("unittest").expect("create temp dir");
+  let tmp_dir = tempdir().expect("create temp dir");
   if content.is_none() {
     return tmp_dir;
   }

tests/storage.rs

@@ -2,10 +2,10 @@ use regex::Regex;
 use schematics::storage::{SimpleStorage, Storage};
 use std::fs::{create_dir, File};
 use std::path::Path;
-use tempdir::TempDir;
+use tempfile::{tempdir, TempDir};
 
 fn get_dir<'a, I: IntoIterator<Item = &'a &'a str>>(content: I) -> TempDir {
-  let tmp_dir = TempDir::new("unittest").expect("create temp dir");
+  let tmp_dir = tempdir().expect("create temp dir");
   let storage_path = tmp_dir.path().join("_filename");
   create_dir(storage_path.clone()).unwrap();
   for path in content {
@@ -93,7 +93,7 @@ fn three_files() {
 
 #[test]
 fn empty_storage() {
-  let dir = TempDir::new("unittest").expect("create temp dir");
+  let dir = tempdir().expect("create temp dir");
   let storage = get_storage(dir.path());
 
   assert!(