For the ones who do not know yet, PowerShell oneGet is a tool that will allow you to manage, your applications on a machine using Powershell.
If you are familiar to Linux apt-get then you you will feel like home reading this blog post.
PowerShell oneGet is only available in Powershell version 5.0
How can I find the powershell version I am using?
There is nothing easier to do in your prompt, use the $PsVErsionTable command to see what powershell version you have installed.
You will have a smiliar return as in the screen shot below. Be sure that psVersion value is at least 5.0.x