api: PEP8 fixes

avocado/api/data_dir.py

@@ -15,11 +15,13 @@ TMP_DIR = os.path.join(ROOT_DIR, 'tmp')
 def get_root_dir():
     return ROOT_DIR
 
+
 def get_tmp_dir():
     if not os.path.isdir(TMP_DIR):
         os.makedirs(TMP_DIR)
     return TMP_DIR
 
+
 def clean_tmp_files():
     if os.path.isdir(TMP_DIR):
         hidden_paths = glob.glob(os.path.join(TMP_DIR, ".??*"))

avocado/api/test.py

 import os
 from avocado.api import data_dir
 
+
 class Test(object):
 
     """
@@ -38,4 +39,4 @@ class Test(object):
 
     def run_once(self):
         test_passed = True
-        return test_passed
\ No newline at end of file
+        return test_passed