tests: Add capture_screenshot_of_output()

Provides a convenience function for JFDI grabbing of a single
screenshot.  Tests that are doing multiple screenshots or other
fanciness probably will bypass this routine and do things more manually,
but this'll provide a reference implementation.  And hopefully there'll
be enough simple cases that this actually is useful.

Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
Reviewed-By: Derek Foreman <derekf@osg.samsung.com>
1 file changed