hits_identification: Identify important siRNA hits
In aspen-shen/RefCells:

This function identifies important siRNA hits as the ones with percentage of healthy-like cells above a threshold

1 2	hits_identification(disease_percent, siRNA_percent, std_siRNA_percent, siRNA_number, siRNA_name, number_of_plates)

`disease_percent`	A vector of healthy-like cell percentage in disease control samples
`siRNA_percent`	A vector of healthy-like cell percentage in siRNA samples
`std_siRNA_percent`	A vector of standard deviations of each siRNA sample across replicate experiments
`siRNA_number`	A vector of ratio between the number of cells in each siRNA sample and mean cell numbers in healthy control samples
`siRNA_name`	A character vector contains the names of each siRNA
`number_of_plates`	The number of replicate experiments