Remove invalid use of jsonschema.compat

Designate was using a private module in jsonschema that has been removed in the jsonschema versions greater than 4.0.0.
This patch removes this use from Designate to allow support for jsonschema newer than 4.0.0.

Change-Id: I66847e801b65911870d51314c985baa0d3c09ef9

designate/schema/format.py

@@ -16,7 +16,6 @@
 import re
 
 import jsonschema
-from jsonschema import compat
 import netaddr
 
 
@@ -56,7 +55,7 @@ draft4_format_checker = jsonschema.draft4_format_checker
 @draft3_format_checker.checks("ip-address")
 @draft4_format_checker.checks("ipv4")
 def is_ipv4(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     try:
@@ -76,7 +75,7 @@ def is_ipv4(instance):
 @draft3_format_checker.checks("ipv6")
 @draft4_format_checker.checks("ipv6")
 def is_ipv6(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     try:
@@ -90,7 +89,7 @@ def is_ipv6(instance):
 @draft3_format_checker.checks("host-name")
 @draft4_format_checker.checks("hostname")
 def is_hostname(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_HOSTNAME, instance):
@@ -101,7 +100,7 @@ def is_hostname(instance):
 
 @draft4_format_checker.checks("ns-hostname")
 def is_ns_hostname(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     # BIND doesn't like *.host.com. see bug #1533299
@@ -114,7 +113,7 @@ def is_ns_hostname(instance):
 @draft3_format_checker.checks("ip-or-host")
 @draft4_format_checker.checks("ip-or-host")
 def is_ip_or_host(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_ZONENAME, instance)\
@@ -130,7 +129,7 @@ def is_ip_or_host(instance):
 @draft3_format_checker.checks("zone-name")
 @draft4_format_checker.checks("zonename")
 def is_zonename(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_ZONENAME, instance):
@@ -141,7 +140,7 @@ def is_zonename(instance):
 
 @draft4_format_checker.checks("srv-hostname")
 def is_srv_hostname(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_SRV_HOST_NAME, instance):
@@ -152,7 +151,7 @@ def is_srv_hostname(instance):
 
 @draft4_format_checker.checks("txt-data")
 def is_txt_data(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if instance.endswith('\\'):
@@ -164,7 +163,7 @@ def is_txt_data(instance):
 @draft3_format_checker.checks("tld-name")
 @draft4_format_checker.checks("tldname")
 def is_tldname(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_TLDNAME, instance):
@@ -176,7 +175,7 @@ def is_tldname(instance):
 @draft3_format_checker.checks("email")
 @draft4_format_checker.checks("email")
 def is_email(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     # A valid email address. We use the RFC1035 version of "valid".
@@ -193,7 +192,7 @@ def is_email(instance):
 
 @draft4_format_checker.checks("sshfp")
 def is_sshfp_fingerprint(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_SSHFP_FINGERPRINT, instance):
@@ -205,7 +204,7 @@ def is_sshfp_fingerprint(instance):
 @draft3_format_checker.checks("uuid")
 @draft4_format_checker.checks("uuid")
 def is_uuid(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_UUID, instance):
@@ -219,7 +218,7 @@ def is_uuid(instance):
 def is_floating_ip_id(instance):
     # TODO(kiall): Apparently, this is used in exactly zero places outside the
     #              tests. Determine if we should remove this code...
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_FIP_ID, instance):
@@ -231,7 +230,7 @@ def is_floating_ip_id(instance):
 @draft3_format_checker.checks("ip-and-port")
 @draft4_format_checker.checks("ipandport")
 def is_ip_and_port(instance):
-    if not isinstance(instance, compat.str_types):
+    if not isinstance(instance, str):
         return True
 
     if not re.match(RE_IP_AND_PORT, instance):