Pass fragment length and SD to salmon quant single-end

Salmon cannot infer fragment length and SD for single-end reads, so they should be passed by user. This should be easy to implement, as we have those parameters already in the samples table because we are using them for kallisto. (Parameters mean and sd).
For argument usage see here.

Maybe option --unmatedReads could be replaced by -r, as that is the expression mentioned in the docs.