[MRG] Removing creation of test folder locally (#400)

* Removing annoying creation of test folder locally.

* Fix for travis.

mne_bids/tests/test_utils.py

@@ -201,17 +201,21 @@ def test_make_folders():
     make_bids_folders(subject='hi', kind='ba', bids_root=bids_root,
                       overwrite=True, verbose=True)
 
-    # Check if bids_root=None creates folders in the current working directory
-    make_bids_folders(subject='hi', session='foo', kind='ba',
-                      bids_root=None)
-    assert op.isdir(op.join(os.getcwd(), 'sub-hi', 'ses-foo', 'ba'))
-
     # Check if a pathlib.Path bids_root works.
     bids_root = Path(_TempDir())
     make_bids_folders(subject='hi', session='foo', kind='ba',
                       bids_root=bids_root)
     assert op.isdir(op.join(bids_root, 'sub-hi', 'ses-foo', 'ba'))
 
+    # Check if bids_root=None creates folders in the current working directory
+    bids_root = _TempDir()
+    curr_dir = os.getcwd()
+    os.chdir(bids_root)
+    make_bids_folders(subject='hi', session='foo', kind='ba',
+                      bids_root=None)
+    assert op.isdir(op.join(os.getcwd(), 'sub-hi', 'ses-foo', 'ba'))
+    os.chdir(curr_dir)
+
 
 def test_check_types():
     """Test the check whether vars are str or None."""