Add several async os functions

Calls of rename, mkdir, rmdir are added together with tests

aiofiles/os.py

@@ -17,7 +17,10 @@ def run(*args, loop=None, executor=None, **kwargs):
 
 
 stat = wrap(os.stat)
+rename = wrap(os.rename)
 remove = wrap(os.remove)
+mkdir = wrap(os.mkdir)
+rmdir = wrap(os.rmdir)
 
 if hasattr(os, "sendfile"):
     sendfile = wrap(os.sendfile)

tests/test_os.py

@@ -1,7 +1,7 @@
 """Tests for asyncio's os module."""
 import aiofiles.os
 import asyncio
-from os.path import join, dirname, exists
+from os.path import join, dirname, exists, isdir
 import pytest
 import platform
 
@@ -29,6 +29,30 @@ def test_remove():
     yield from aiofiles.os.remove(filename)
     assert exists(filename) is False
 
+
+@asyncio.coroutine
+@pytest.mark.asyncio
+def test_mkdir_and_rmdir():
+    """Test the mkdir and rmdir call."""
+    directory = join(dirname(__file__), 'resources', 'test_dir')
+    yield from aiofiles.os.mkdir(directory)
+    assert isdir(directory)
+    yield from aiofiles.os.rmdir(directory)
+    assert exists(directory) is False
+
+
+@asyncio.coroutine
+@pytest.mark.asyncio
+def test_rename():
+    """Test the rename call."""
+    old_filename = join(dirname(__file__), 'resources', 'test_file1.txt')
+    new_filename = join(dirname(__file__), 'resources', 'test_file2.txt')
+    yield from aiofiles.os.rename(old_filename, new_filename)
+    assert exists(old_filename) is False and exists(new_filename)
+    yield from aiofiles.os.rename(new_filename, old_filename)
+    assert exists(old_filename) and exists(new_filename) is False
+
+
 @asyncio.coroutine
 @pytest.mark.skipif('2.4' < platform.release() < '2.6.33',
                     reason = "sendfile() syscall doesn't allow file->file")