Fix stdlib and Puppet version requirements in metadata.json

[juniorsysadmin]

Official stdlib docs state that stdlib 2.x is not compatible with Puppet 3.x.
We require Puppet versions 3.4.0 or greater due to #121

[igalic]

what's up with the test failures?

 1) nodejs when run on Debian release 7.0 with legacy_debian_symlinks set to true the file resource /usr/bin/node should be in the catalog
     Failure/Error: should contain_file('/usr/bin/node')
     Puppet::Error:
       undefined method `ref' for nil:NilClass on node testing-worker-linux-f25aadab-1-20168-linux-8-61003744
     # /home/travis/.rvm/gems/ruby-1.9.3-p551/gems/puppet-3.4.3/lib/puppet/resource/catalog.rb:527:in `block in to_catalog'

[juniorsysadmin]

The test were failing for some reason only on 3.4.0 - I have no idea why. Since the travis.yml has now changed on master, I have rebased and tests on the new Travis CI matrix are now all green.

[juniorsysadmin]

Before this was moved across, tests were okay. This should probably be merged in before the next release is cut. Any objections?

[ffrank]

Can you make this into a new PR so that Travis can greenlight it once more? Call me a paranoid nitpick :)

[nibalizer]

@ffrank why does it need a new PR? I see greens from travis and here: http://planck.nibalizer.com:5000/modules/puppet-community/puppet-nodejs

[ffrank]

Rebase apparently did the trick? I'm happy either way 👍