test: use zero-argument super() shortcut (Python 3.0+)

as defined in PEP 3135:

"The new syntax:

    super()

is equivalent to:

    super(__class__, <firstarg>)

where __class__ is the class that the method was defined in, and <firstarg> is
the first parameter of the method (normally self for instance methods, and cls
for class methods)."

test/functional/test_framework/script.py

@@ -97,7 +97,7 @@ class CScriptOp(int):
             return _opcode_instances[n]
         except IndexError:
             assert len(_opcode_instances) == n
-            _opcode_instances.append(super(CScriptOp, cls).__new__(cls, n))
+            _opcode_instances.append(super().__new__(cls, n))
             return _opcode_instances[n]
 
 # Populate opcode instance table
@@ -372,7 +372,7 @@ class CScriptTruncatedPushDataError(CScriptInvalidError):
     """Invalid pushdata due to truncation"""
     def __init__(self, msg, data):
         self.data = data
-        super(CScriptTruncatedPushDataError, self).__init__(msg)
+        super().__init__(msg)
 
 
 # This is used, eg, for blockchain heights in coinbase scripts (bip34)
@@ -458,14 +458,14 @@ class CScript(bytes):
 
     def __new__(cls, value=b''):
         if isinstance(value, bytes) or isinstance(value, bytearray):
-            return super(CScript, cls).__new__(cls, value)
+            return super().__new__(cls, value)
         else:
             def coerce_iterable(iterable):
                 for instance in iterable:
                     yield cls.__coerce_instance(instance)
             # Annoyingly on both python2 and python3 bytes.join() always
             # returns a bytes instance even when subclassed.
-            return super(CScript, cls).__new__(cls, b''.join(coerce_iterable(value)))
+            return super().__new__(cls, b''.join(coerce_iterable(value)))
 
     def raw_iter(self):
         """Raw iteration