fixed bugs
fixed bugs

fixed bugs where logq values would not be plotted if zero; fixed a bug
where labels appeared because of a bad column name; fixed bug where
plot_enrichment modified data frame each time it was called.

raymond91125/TissueEnrichmentAnalysis,raymond91125/TissueEnrichmentAnalysis,dangeles/TissueEnrichmentAnalysis,raymond91125/tissue_enrichment_tool_hypergeometric_test,dangeles/TissueEnrichmentAnalysis,dangeles/tissue_enrichment_tool_hypergeometric_test