Update method-gridSearch.R

[nickhsmith]

avoids the corner case where a gene that modified for outlier injection is set to 0 resulting in a gene that has no reads across all samples.

if samples A, B, C have 0 counts and sample D has 100 counts for geneX. If geneX and sample D are modified to 0 to find outliers then in this new counts matrix geneX has no reads for all samples resulting in a failed checkCountRequirements check.

There are other ways to avoid this corner case, but seems simplest.

[nickhsmith]

A more specific corner case handling. Injected 0 count outliers are allowed, as long as the other samples have at least 1 non-zero count for that gene.