Remove file extension when building SimpleLayout

When using simple_layout, the setup function is adding ".yaml" to the
file names it is creating (meaning playbooks get names like
"playbooks/run/integration.yaml.yaml").

This is hidden by the implied playbook extension matching, which
searches for files with an added ".yaml" so finds them
anyway. However, simple_layout unit tests then break when this
matching is removed (Ie2519f2b4144761b8e4d17ec3299cf4238e16f08).

Change-Id: Ibfacd73840b995873156f1687860ea6792b30b26
1 file changed