student_test: Simplify and just use scipy for it

git-svn-id: https://tpsh.dc.uba.ar/svn/cpfusaro-bdtp2@60 3a36324f-a680-47ab-a1ff-96278a0c223d
student_test: Interpretar correctamente el nivel del test

git-svn-id: https://tpsh.dc.uba.ar/svn/cpfusaro-bdtp2@61 3a36324f-a680-47ab-a1ff-96278a0c223d
student_test: s/probabilidad/nivel de certeza/ es mas correcto asi

git-svn-id: https://tpsh.dc.uba.ar/svn/cpfusaro-bdtp2@62 3a36324f-a680-47ab-a1ff-96278a0c223d