use standard library json instead of simplejson

Based on https://review.openstack.org/#/c/240596/

Change-Id: I7f5be799ea7dcb49b7d9df830f1f15ee9a02b3ca

bin/swauth-cleanup-tokens

@@ -16,12 +16,9 @@
 
 from datetime import datetime
 from datetime import timedelta
-try:
-    import simplejson as json
-except ImportError:
-    import json
 from getpass import getpass
 import gettext
+import json
 from optparse import OptionParser
 import re
 from sys import argv

bin/swauth-list

@@ -14,12 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-try:
-    import simplejson as json
-except ImportError:
-    import json
 from getpass import getpass
 import gettext
+import json
 from optparse import OptionParser
 from sys import argv
 from sys import exit

bin/swauth-set-account-service

@@ -14,12 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-try:
-    import simplejson as json
-except ImportError:
-    import json
 from getpass import getpass
 import gettext
+import json
 from optparse import OptionParser
 from sys import argv
 from sys import exit

swauth/middleware.py

@@ -18,10 +18,7 @@ from hashlib import sha1
 import hmac
 from httplib import HTTPConnection
 from httplib import HTTPSConnection
-try:
-    import simplejson as json
-except ImportError:
-    import json
+import json
 from time import gmtime
 from time import strftime
 from time import time

test/unit/test_middleware.py

@@ -14,10 +14,7 @@
 # limitations under the License.
 
 from contextlib import contextmanager
-try:
-    import simplejson as json
-except ImportError:
-    import json
+import json
 from time import time
 import unittest