Fixed SafeConfigParser deprecation warning for py3

Using six.PY3 as configparser.SafeConfigParser in py2 got
renamed to configparser.ConfigParser in py3. In order to
keep the codebase running on both version, we are using
it.

Change-Id: I78471e3d0962cda610c22641787d80103eb413b0

config_tempest/main.py

@@ -37,6 +37,7 @@ obtained by querying the cloud.
 import argparse
 import logging
 import os
+import six
 import sys
 
 import os_client_config
@@ -132,7 +133,10 @@ def read_deployer_input(deployer_input_file, conf):
     """
     LOG.info("Adding options from deployer-input file '%s'",
              deployer_input_file)
-    deployer_input = configparser.SafeConfigParser()
+    if six.PY3:
+        deployer_input = configparser.ConfigParser()
+    else:
+        deployer_input = configparser.SafeConfigParser()
     deployer_input.read(deployer_input_file)
     for section in deployer_input.sections():
         # There are no deployer input options in DEFAULT

config_tempest/tempest_conf.py

@@ -14,6 +14,7 @@
 # under the License.
 
 import os
+import six
 import sys
 
 from config_tempest import constants as C
@@ -34,7 +35,10 @@ class TempestConf(configparser.SafeConfigParser):
 
     def __init__(self, write_credentials=True, **kwargs):
         self.write_credentials = write_credentials
-        configparser.SafeConfigParser.__init__(self, **kwargs)
+        if six.PY3:
+            configparser.ConfigParser.__init__(self, **kwargs)
+        else:
+            configparser.SafeConfigParser.__init__(self, **kwargs)
 
     def get_bool_value(self, value):
         """Returns boolean value of the string value given.
@@ -101,7 +105,10 @@ class TempestConf(configparser.SafeConfigParser):
         if priority:
             self.priority_sectionkeys.add((section, key))
         C.LOG.debug("Setting [%s] %s = %s", section, key, value)
-        configparser.SafeConfigParser.set(self, section, key, value)
+        if six.PY3:
+            configparser.ConfigParser.set(self, section, key, value)
+        else:
+            configparser.SafeConfigParser.set(self, section, key, value)
         return True
 
     def write(self, out_path):
@@ -111,7 +118,10 @@ class TempestConf(configparser.SafeConfigParser):
                        "writing credentials is disabled.")
             self.remove_values(C.ALL_CREDENTIALS_KEYS)
         with open(out_path, 'w') as f:
-            configparser.SafeConfigParser.write(self, f)
+            if six.PY3:
+                configparser.ConfigParser.write(self, f)
+            else:
+                configparser.SafeConfigParser.write(self, f)
 
     def remove_values(self, to_remove):
         """Remove values from configuration file specified in arguments.