outdated replace directive in go.mod

[Morty-luo]

It seems that mcuadros/ascode does not depend on github.com/hashicorp/hcl2 any more, both directly and indirectly. So, replace usage left in go.mod makes no sense. Should it be dropped?

$ go mod why -m github.com/hashicorp/hcl2
# github.com/hashicorp/hcl2
(main module does not need module github.com/hashicorp/hcl2)

https://github.com/mcuadros/ascode/blob/master/go.mod#L42

replace github.com/hashicorp/hcl2 => github.com/mcuadros/hcl2 v0.0.0-20190711172820-dd3dbf62a554