Update to new image and job format (#498)
Update to new image and job format (#498)

The current Ubuntu image we are using will be deprecated on December 1, 2018, this moves to the "new" VM image
IronLanguages/ironpython3,IronLanguages/ironpython3,IronLanguages/ironpython3,IronLanguages/ironpython3,IronLanguages/ironpython3,IronLanguages/ironpython3