Bump PARROT_REVISION to be closer to 2.7.0 release.
Bump PARROT_REVISION to be closer to 2.7.0 release.

cygx/nqp,cygx/nqp,perl6/nqp-rx,cygx/nqp,perl6/nqp-rx,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp,cygx/nqp