1.0.1 isn't on pypi

[Ross Burton]

Summary says it all really: https://pypi.org/project/build/#files still only has 1.0.0.

[Henry Schreiner]

1.0.1 and 1.0.2 were on PyPI. In 2015. :)

Finally got 1.0.3 out, shouldn't have any more missing numbers.

#679 #681 #677 for context.