Bad dependency

```
$ go get -u github.com/raviqqe/liche
package github.com/russross/blackfriday/v2: cannot find package "github.com/russross/blackfriday/v2" in any of:
	/home/go/src/github.com/russross/blackfriday/v2 (from $GOROOT)
	/home/ccallegar/go/src/github.com/russross/blackfriday/v2 (from $GOPATH)
```

See https://github.com/russross/blackfriday/issues/565