refine_key should capture all response options

[statisfactions]

Looks like refine_key only captures options that are ever marked as correct---i.e. that appear at least once in the row_key.

math_char = math
math_char[,-1] = apply(math_char[,-1], 2, as.character)

math_char[2, 2] = "other option"

test_that("refine_key catches all response options", {
  refined_key = QME:::refine_key(math_key, math_char)
  expect_true("other option" %in% refined_key$response)
})

[statisfactions]

This causes errors in distractor analysis:

analyze(math_char, math_key)
# Error in `[.data.frame`(indicators, , distractors, drop = FALSE) : 
 # undefined columns selected