exclude spec/fixtures/** from puppet-syntax checking
puppet-lint should ignore pkg/**
add puppet 3.3.0 to travis test matrix
set stdlib requirement to 3.0.0
add GFMD highlighting to README
tidy Rakefile quotes
remove usage of $::lsbmajdistrelease fact

Instead use $::operatingsystemmajrelease as this fact is not dependant on
redhat-lsb being present on the system.