Remove "manifesto" from .gitignore.
Remove "manifesto" from .gitignore.

Prep work for replacing manifesto.go with a Python script called
"manifesto".

Reviewed-by: Alex Elder <f429030cf5c0faf36fac3d102073b6e63a647baa@linaro.org>
Signed-off-by: Marti Bolivar <35e491f5b70a779e5455b1f9617e0073292369ca@leaflabs.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@google.com>

ChrisMyerchin/manifesto,gregkh/manifesto,projectara/manifesto