Readme major_scale example is wrong

[asteriskman7]

The readme has an example that uses melopy.major_scale('C5') but there is no major_scale function. I think this should be something like melopy.generateScale('major', 'C5').

I will be happy to fix this if someone can confirm that I'm not just missing something.

If no one replies in a week or so I'll assume I'm right and make the change.