Update Batch SDK to use new API version 2018-12-01#4072

Merged

lmazuel merged 3 commits intoAzure:masterfrom

Dec 20, 2018

Commits on Dec 12, 2018

Update data plane SDK with new API 2018-12-01
xingwu1
committed

Commits on Dec 17, 2018

Update test cases for new API.
xingwu1
committed

Commits on Dec 18, 2018

Merged model classes into single file.
xingwu1
committed