move estimate_fee back to wallet

lib/transaction.py

@@ -715,15 +715,6 @@ class Transaction:
     def is_final(self):
         return not any([x.get('sequence') < 0xffffffff - 1 for x in self.inputs()])
 
-    @classmethod
-    def fee_for_size(self, relay_fee, fee_per_kb, size):
-        '''Given a fee per kB in satoshis, and a tx size in bytes,
-        returns the transaction fee.'''
-        fee = int(fee_per_kb * size / 1000.)
-        if fee < relay_fee:
-            fee = relay_fee
-        return fee
-
     @profiler
     def estimated_size(self):
         '''Return an estimated tx size in bytes.'''
@@ -734,10 +725,6 @@ class Transaction:
         '''Return an estimated of serialized input size in bytes.'''
         return len(self.serialize_input(txin, -1, -1)) / 2
 
-    def estimated_fee(self, relay_fee, fee_per_kb):
-        '''Return an estimated fee given a fee per kB in satoshis.'''
-        return self.fee_for_size(relay_fee, fee_per_kb, self.estimated_size())
-
     def signature_count(self):
         r = 0
         s = 0