Merge pull request #10 from agbeltran/dev

Changed condition for 'one tailed test', assigned URIs
adding exact binomial test, metadata and adding restriction to hypergeometric test, closes #6
adding axiom on exact binomial distribution as i forgot to set binomial distribution as input closes #6
adding design matrix and contrast, curation set to pending final vetting
adding stub for statistical inference
Changes related to the definition of ratio