Making .import.rio_xls() follow the same format at .import.rio_xlsx()

[bokov]

Please specify whether your issue is about:

• a possible bug
• a question about package functionality
• a suggested code or documentation change, improvement to the code, or feature request

Minor tweak.

readxl::read_xls() and readxl::read_xlsx() have identical call signatures:

all.equal(args(readxl::read_xlsx),args(readxl::read_xlsx))

# [1] TRUE

Yet .import.rio_xls() is completely different from .import.rio_xlsx(). If the answer to #223 is affirmative, while I'm in there anyway, I could revise .import.rio_xls() to follow the same pattern as .import.rio_xls().