apa 0.3.0

New features

• Add LaTeX math output format (#3)

Bug fixes and minor improvements

• Fix error in anova_apa when specifying the effect argument
• Fix printing of p-values if p = 1.
• Add missing else in anova_apa. (@stegmannks, #6)
• Fix error in calculation of sample size from degrees of freedom in Cohen's d
  for dependent samples (@lcreteig, #7)