Changes in version 1.11.1                        

    o   *corrected bugs that occur when mixture models include at most 1 predictor

                        Changes in version 1.9.1                        

    o   *modified package so that normalization function does not output data 
	when any model parameters are not possible to estimate. 
	*added function metabPlot to plot pre vs. post normalization 
	metabolite abundances. 
	*updated mixnorm vignette

                        Changes in version 1.7.3                        

    o   *modified package functions to handle situations where metabolites are entirely 
	missing for all levels of a categorical predictor in the mixture model.

                        Changes in version 1.7.1                        

    o   *modified package functions to handle situations where metabolites are entirely 
	missing for a particular level of a categorical predictor in the mixture model.

                        Changes in version 1.3.6                        

    o   *made small modifications to arguments for function mixnorm
	*added vignette for mixnorm

                        Changes in version 1.3.1                        

    o   *added mixnorm function for normalization of non-targeted metabolomics studies