Add async remove function

Relevent test is also added

aiofiles/os.py

@@ -17,6 +17,7 @@ def run(*args, loop=None, executor=None, **kwargs):
 
 
 stat = wrap(os.stat)
+remove = wrap(os.remove)
 
 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
+from os.path import join, dirname, exists
 import pytest
 import platform
 
@@ -17,6 +17,18 @@ def test_stat():
     assert stat_res.st_size == 10
 
 
+@asyncio.coroutine
+@pytest.mark.asyncio
+def test_remove():
+    """Test the remove call."""
+    filename = join(dirname(__file__), 'resources', 'test_file2.txt')
+    with open(filename, 'w') as f:
+        f.write('Test file for remove call')
+
+    assert exists(filename)
+    yield from aiofiles.os.remove(filename)
+    assert exists(filename) is False
+
 @asyncio.coroutine
 @pytest.mark.skipif('2.4' < platform.release() < '2.6.33',
                     reason = "sendfile() syscall doesn't allow file->file")