test_type - 'Nil hypothesis test', meaning a test against H0 = 0
outcome_variable_name - Name of the outcome variable
effect - Label for the effect being tested
null_words - Express the null in words
confidence - Confidence level, integer (95 for 95%, etc.)
LL - Lower boundary of the confidence% CI for the effect
UL - Upper boundary of the confidence% CI for the effect
CI - Character representation of the CI for the effect
CI_compare - Text description of relation between CI and null
t - If applicable, t value for hypothesis test
df - If applicable, degrees of freedom for hypothesis test
p - If applicable, p value for hypothesis test
p_result - Text representation of p value obtained
null_decision - Text represention of the decision for the null
conclusion - Text representation of conclusion to draw
significant - TRUE/FALSE if significant at alpha = 1-CI