Appveyor MSVC build issue

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I was trying to update the appveyor script for boost.python PR #271 and changed it to pip install the released faber 0.3 however the builds are failing.

Python 2.7

skipped src\msvc-14.0\x86_64\shared\list.obj for lack of src\msvc-14.0\x86_64\shared\list.d

Python 3.6

...skipped src\msvc-14.0\x86_64\shared\converter\builtin_converters.obj for lack of src\msvc-14.0\x86_64\shared\converter\builtin_converters.d...

Full details of failing builds: https://ci.appveyor.com/project/stefanseefeld/python/builds/25582056

Reverting to snapshot/2018-04-08 fixes the issue.