Fix is_pe declaration so it works without is_pe

Signed-off-by: Ken Barber <ken@bob.sh>
Test against string 'true' not boolean

Because facter likes to convert booleans to strings

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #123 from kbarber/maint/master/fix_is_pe

Fix is_pe declaration so it works without is_pe