Remove sample types from database
     
    
    Usage
    deleteSampleType(conn_handler, sample_type, verbose = TRUE)
 
    
    Arguments
- conn_handler
- A handler uses to establish connection to the database
obtained from SigRepo::newConnhandler() (required) 
- sample_type
- A list of sample types to be removed (required) 
- verbose
- a logical value indicates whether or not to print the
diagnostic messages. Default is - TRUE.