scripts: csv.py: Added float mod support

Mainly for consistency with int operators, though it's unclear if either
mod is useful in the context of csv.py and related scripts.

This may be worth reverting at some point.

scripts/csv.py

@@ -182,6 +182,8 @@ class RFloat(co.namedtuple('RFloat', 'x')):
     def __div__(self, other):
         return self.__class__(self.x / other.x)
 
+    __mod__ = RInt.__mod__
+
 # fractional fields, a/b
 class RFrac(co.namedtuple('RFrac', 'a,b')):
     __slots__ = ()