check_columns: Check for the presence of named columns
In evanbiederstedt/sandbox: The functions

Check for the presence of named columns

1	check_columns(which_names, input, input_name, function_name)

`which_names`	Column names to check, e.g. c("peaks", "genes")
`input`	The names() of this will be checked.
`input_name`	Name of the input, e.g. "start_params" just to make it identifiable if an error message is returned.
`function_name`	Name of function for which this test is carried out. Again, just to make the returning error message a bit more readable. This helps with debugging if you're wrapping many functions within each other.