Multi pkg example

[arkwave]

As discussed, here's a small example on an application that uses sqlalchemy and plotly.

• Added in the steps involving extracting the pre-compiled scipy/numpy binaries from Christoph Gohlke's website because I ran into DLL-related import errors with these packages. Building these packages from wheels didn't work, and this was the only workaround that I was able to find.

• I also recommended building matplotlib from wheels to avoid DLL-based import errors.

• Also specified dependencies for pandas, plotly and sqlalchemy.

Hope this helps.

[takluyver]

Thanks for working on this, but I think that 'multi package' is a bit too general to be useful. We've already got some examples of building packages with matplotlib and numpy, and now that scipy is putting wheels on PyPI, that should be straightforward as well.

Once PEP 517 is finished and implemented, I might add support for building wheels from source packages, which would let us get more packages (like plotly and sqlalchemy) from PyPI.