deliver selected FC or sample for BP analysis

At present we cant deliver selected "flowcell" or "sample" for BP data. `flist` is nothing but list for `-bcbb.config.yaml` files with absolute path. So this PR should fix it. 
So this this used with `-S [bcbb-config.yaml]` Just a bit confusing since the program options say that you can use a path to the readfile(?) or use a sample ID when using `-S`, see [line 46](https://github.com/senthil10/scilifelab/blob/master/scilifelab/pm/core/deliver.py#L46)