Update licenses (#46)

I ran this command to regenerate the license file:

```
go run $GOPATH/pkg/mod/github.com/google/[email protected]/tools/license_serializer/license_serializer.go -output assets
```

I also adjusted the path used for the license DB file, since
licenseclassifier automatically uses the `licenses.db` path in whatever
`-output` directory you give it.

Author: gtback

assets/assets.go

@@ -19,7 +19,7 @@ package assets // import "go.elastic.co/go-licence-detector/assets"
 
 import _ "embed"
 
-//go:embed licence.db
+//go:embed licenses.db
 var LicenceDB []byte
 
 //go:embed rules.json