Merge pull request #3 from janhenrikbern/master

Assert float input type for Scalar class

minitorch/scalar.py

@@ -45,7 +45,7 @@ class Scalar(Variable):
 
     def __init__(self, v, back=History(), name=None):
         super().__init__(back, name=name)
-        self.data = v
+        self.data = float(v)
 
     def __repr__(self):
         return "Scalar(%f)" % self.data