Implement multiple YAML documents inside a .vespene file

[mpdehaan]

Per forum discussion, a .vespene file should be able to define more than one project:

---
name: "Tommys Project"
script: "scripts/example.sh"
timeout: 60
repo_branch: master
variables:
   testvar: "hello!"
   luggage_code: "5150"
worker_pool: 'tutorial-pool'
---
name: "Tommys Second Project"
script: "scripts/example.sh"
timeout: 60
repo_branch: master
variables:
   testvar: "hehehoho"
   luggage_code: "5150"
worker_pool: 'tutorial-pool'