Fix(steps): Typing steps are bypassed

Useless steps where complex objects were built are not shown. I create
a typing function which is called when compute raise
NotImplementedError.

mapytex/calculus/core/compute/divide.py

@@ -10,6 +10,7 @@
 Divide MO
 """
 
+from decimal import Decimal
 from multipledispatch import Dispatcher
 from ..tree import Tree
 from ..MO.mo import MO, MOnumber
@@ -66,12 +67,22 @@ def divide_filter(left, right):
 def monumber_monumber(left, right):
     """ Divide 2 monumbers and return a MOFraction
 
+    >>> a = MOnumber(4)
+    >>> b = MOnumber(6.2)
+    >>> monumber_monumber(a, b)
+    Decimal('0.6451612903225806266768278939')
     >>> a = MOnumber(4)
     >>> b = MOnumber(6)
     >>> monumber_monumber(a, b)
-    <MOFraction 4 / 6>
+    Traceback (most recent call last):
+    ...
+    NotImplementedError: Can't divide 2 int. Need to create a Fraction instead
     """
-    return MOFraction(left, right)
+    if type(left.value) in [float, Decimal] or \
+            type(right.value) in [float, Decimal]:
+        return left / right
+    else:
+        raise NotImplementedError("Can't divide 2 int. Need to create a Fraction instead")
 
 @divide.register(MOnumber, MOFraction)
 @special_case(divide_filter)