Panic when the last function in the chain has no return value

[mauricioklein]

When the last function in the chain returns nothing, the system panics:

f1 := func() int { return 0 }
f2 := func(x int) {}

New().Chain(f1, f2).Unwrap()

For the case above, the Unwrap method is supposed to return any zero-value (like an empty string) and a nil error

[mauricioklein]

Fixed by release v1.0.2