Update init.pp

Was including the development (unstable) even when flag was false.
#pr-62 hasn't been merged yet... so...
Fix for chrislea ppa that already installs npm
Merge pull request #68 from barthoda/master

Ubuntu uses uppercase for the operatingsystem fact
Merge pull request #64 from vpassapera/patch-1

Fix ubuntu development package being installed when dev flag is set to false