Clean up R CMD check NOTES

[gowerc]

* checking R code for possible problems ... NOTE
as_fmt_char.list : <anonymous>: no visible global function definition
  for ‘capture.output’
Undefined global functions or variables:
  capture.output
Consider adding
  importFrom("utils", "capture.output")
  
  * checking Rd \usage sections ... NOTE
Documented arguments not in \usage in Rd file 'identify_column_order_differences.Rd':
  ‘COMP’