GR score calculation is wrong

https://github.com/theislab/destiny/blob/8cc0bffe8ac72989ac6a0511e5aa71132edab632/R/gene-relevance-plotting-gr-map.r#L64

should be 

`scores <- counts_valid$Freq / (sum(counts_valid$Freq)/n_top)`

Thanks @timcyu, totally forgot about this e-mail from 5 years ago 😅 