* add pytest skips around tests that require certain ops to be installed

* ZeRO-Offload (squash) (#381)
Co-authored-by: NOlatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: NReza Yazdani <reyazda@microsoft.com>
Co-authored-by: NJeff Rasley <jerasley@microsoft.com>
Co-authored-by: NJie <37380896+jren73@users.noreply.github.com>
Co-authored-by: NArash Ashari <arashari@microsoft.com>
Co-authored-by: NReza Yazdani <reyazda@microsoft.com>
Co-authored-by: NSamyam Rajbhandari <samyamr@microsoft.com>
Co-authored-by: NShaden Smith <Shaden.Smith@microsoft.com>
Co-authored-by: Narashashari <arashashari@ArashMSLaptop.redmond.corp.microsoft.com>
Co-authored-by: NRezaYazdaniAminabadi <44502768+RezaYazdaniAminabadi@users.noreply.github.com>
Co-authored-by: NReza Yazdani <reyazda@microsoft.com>
Co-authored-by: NSamyam Rajbhandari <samyamr@microsoft.com>
Co-authored-by: NShaden Smith <Shaden.Smith@microsoft.com>