Deprecate SpfRecord

CHANGELOG.md

@@ -15,6 +15,8 @@
   common records across all zones using the provider. It can be used stand-alone
   or in combination with zone files and/or split configs to aid in DRYing up DNS
   configs.
+* SpfRecord is formally deprecated with an warning and will become a
+  ValidationError in 2.x
 
 #### Stuff
 

octodns/record/spf.py

@@ -10,5 +10,11 @@ class SpfRecord(_ChunkedValuesMixin, Record):
     _type = 'SPF'
     _value_type = _ChunkedValue
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.log.warning(
+            'The SPF record type is DEPRECATED in favor of TXT values and will become an ValidationError in 2.0'
+        )
+
 
 Record.register_type(SpfRecord)