Update python buildpack to allow pip upgrade
Update python buildpack to allow pip upgrade

moscowpython/moscowpython,VladimirFilonov/moscowdjango,moscowpython/moscowpython,moscowdjango/moscowdjango,moscowdjango/moscowdjango,moscowpython/moscowpython,VladimirFilonov/moscowdjango,moscowdjango/moscowdjango,VladimirFilonov/moscowdjango