When following the release guide, installing from testpypi using the
`-i` flag failed on my, and at least one other's, development machines.
The cause of the failure appears to be that pip would look for packages,
such as `LogBook` or `pandas` on `testpypi`. However many dependencies
do not have versions that meet our version criteria. (e.g. pandas does
not have a version between 0.16.0 and 0.18.0 on testpypi.)
Instead, use `--extra-index-url` so that other packages can use `pypi`
as a fallback server, instead of being limited to `testpypi`.
as well as tooling and docs to generate this for each release
Also moved Cython files to package_data, so that we install them,
instead of just packaging them.
Eddie Hebert