Add dotnet core YAML template
We have a template for dotNet but its around a windows based runner. We should add a dotNet core YAML template to https://gitlab.com/gitlab-org/gitlab-ce/tree/master/lib/gitlab/ci/templates
We have a template for dotNet but its around a windows based runner. We should add a dotNet core YAML template to https://gitlab.com/gitlab-org/gitlab-ce/tree/master/lib/gitlab/ci/templates