Assert no conflicting packages in build

[jondequinor]

A package version conflict is when package a depends on z==1 and package b depends on z>=2.5. A build process that produces a conflicting build (i.e. installs an arbitrary z in this case), is a faulty one. In the build process, we disable all dependency tooling in pip when downloading/building/installing python code into the build. So the only thing that stands between authoring a release file, and a conflicting build, is people and social convention.

For python packages, pip check in the build process could indicate if the build is conflicting or not.