Errors occur when go get -u github.com/swaggo/swag/cmd/swag

[shenzhigang]

Describe the bug

go: finding github.com/swaggo/swag/cmd/swag latest
go: finding github.com/swaggo/swag/cmd latest
go: finding golang.org/x/net latest
go: finding github.com/PuerkitoBio/urlesc latest
go: finding golang.org/x/tools latest
# github.com/cpuguy83/go-md2man/md2man
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/md2man.go:11:16: undefined: blackfriday.EXTENSION_NO_INTRA_EMPHASIS
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/md2man.go:12:16: undefined: blackfriday.EXTENSION_TABLES
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/md2man.go:13:16: undefined: blackfriday.EXTENSION_FENCED_CODE
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/md2man.go:14:16: undefined: blackfriday.EXTENSION_AUTOLINK
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/md2man.go:15:16: undefined: blackfriday.EXTENSION_SPACE_HEADERS
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/md2man.go:16:16: undefined: blackfriday.EXTENSION_FOOTNOTES
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/md2man.go:17:16: undefined: blackfriday.EXTENSION_TITLEBLOCK
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/md2man.go:19:29: too many arguments to conversion to blackfriday.Markdown: blackfriday.Markdown(doc, renderer, extensions)
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/roff.go:19:9: cannot use &roffRenderer literal (type *roffRenderer) as type blackfriday.Renderer in return argument:
        *roffRenderer does not implement blackfriday.Renderer (missing RenderFooter method)
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/roff.go:102:11: undefined: blackfriday.LIST_TYPE_ORDERED
../../go/pkg/mod/github.com/cpuguy83/go-md2man@v1.0.10/md2man/roff.go:102:11: too many errors

Your swag version
1.6.4

Your go version
1.13.5

Desktop (please complete the following information):

• OS: macos

[shenzhigang]

Duplicated to #598