Replace readfp() with read_file()

The readfp() of ConfigParser has been deprecated since
python3.2[1]. Replace it with read_file()

[1]:
https://docs.python.org/3/library/configparser.html#configparser.ConfigParser.readfp

Signed-off-by: Han Han <hhan@redhat.com>

did/base.py

@@ -99,7 +99,7 @@ def __init__(self, config=None, path=None):
         # Parse the config from file
         try:
             log.info("Inspecting config file '{0}'.".format(path))
-            self.parser.readfp(codecs.open(path, "r", "utf8"))
+            self.parser.read_file(codecs.open(path, "r", "utf8"))
         except IOError as error:
             log.debug(error)
             Config.parser = None