Mono.Posix.dll not included in nuget package or referenced via package

[pde-cds]

Description

Using IronPython 2.7.12 nuget package from Nuget.org.
IronPython.dll references Mono.Posix on .NET 4.5 build, but its neither included in the package nor referenced via another nuget package.

Steps to Reproduce

1. Loading IronPython Assembly
2. Fails due to not existing Mono.Posix.dll in version 4.0.0.0

Expected behavior: [What you expected to happen]
nuget package should include everything to run IronPython.dll or should reference the right nuget packages
Actual behavior: [What actually happened]
nuget is incomplete to be loaded

Versions

IronPython 2.7.12