Default return value for extended_div (#313)

* Give extended_div a default return value

* Fix missing end

Author: dpsanders

src/intervals/arithmetic.jl

@@ -226,9 +226,9 @@ function extended_div(a::Interval{T}, b::Interval{T}) where T<:Real
         end
     elseif 0 ∈ a && 0 ∈ b
         return (entireinterval(S), emptyinterval(S))
-    else
-        return (a / b, emptyinterval(S))
     end
+    
+    return (a / b, emptyinterval(S))
 end
 
 //(a::Interval, b::Interval) = a / b    # to deal with rationals