Investigate CalculateClusterEnrichment edge case

[GWMcElfresh]

When a cluster is 100% comprised of a single individual, CalculateClusterEnrichment fails in an unexpected way.

It is probably here:

CellMembrane/R/Analysis.R

Lines 384 to 390 in 85ff116

	for (cluster in unique(clusterProportionsDataFrame[[clusterField]])) {
	clusterProportionsSubset <- clusterProportionsDataFrame[clusterProportionsDataFrame[[clusterField]] == cluster,]
	groupOneProportions <- clusterProportionsSubset[clusterProportionsSubset[[treatmentField]] == unique(clusterProportionsSubset[[treatmentField]])[1],]$SubjectClusterProportion
	groupTwoProportions <- clusterProportionsSubset[clusterProportionsSubset[[treatmentField]] == unique(clusterProportionsSubset[[treatmentField]])[2],]$SubjectClusterProportion
	#if a subject is missing from one of the groups, we need to impute the missing percentage with a zero.
	#I can't figure out a way to pass a "TreatmentGroup by Subjects" table succinctly to dplyr::complete, but it will be really obvious at this stage, so we can impute.
	if (length(groupOneProportions) != length(groupTwoProportions)) {

If a cluster only has one subject, then it probably only has one group and this check fails.