remove apt-cache configuration after build
remove apt-cache configuration after build

we should not have this around after the build finished.
other people can't use our cache anyway
This fixes #27

PuZZleDucK/pixelated-platform,PuZZleDucK/pixelated-platform,PuZZleDucK/pixelated-platform,pixelated/puppet-pixelated,pixelated/puppet-pixelated,pixelated/puppet-pixelated,PuZZleDucK/pixelated-platform,pixelated/puppet-pixelated