CHEF-4890: Allow gem upgrades

This was preventing chef from finding the candidate version when
upgrading a gem and assuming there was nothing to do
Make sure to call chef-client and knife that we just built, not
just some random ones hanging around in $PATH.
Add option --prevew-archive to `knife cookbook site share`
updates by comment. #1724

- Fix Typo prevew_archive to preview_archive.
- Change message priority from warn to info.
- Add few specs.
Merge remote-tracking branch 'upstream/master' into prevew_archive_before_site_share
change option name --preview-archive to --[no-]upload
Merge remote-tracking branch 'upstream/master' into prevew_archive_before_site_share
add rhel 7 e2e test
use a flavor that supports HVM

rhel-7 seems to be HVM-only
Do not use :Win32 outside of let, describe, it blocks since we don't have it ready yet.
* Dscl user provider changes to support Mac 10.7, 10.8 & 10.9.
* Make the dscl user provider password handling idempotent.
* Refactor / modernize dscl user provider unit tests.
* Functional tests for dscl user provider.
Updates based on PR comments.
use ec2-user for rhel7 image
Merge pull request #1814 from opscode/sersut/travis-fix

Do not use :Win32 outside of let, describe, it blocks since we don't have it ready yet.
e2e test on rhel found a bug
Changelog information for user dscl provider updates.
Merge pull request #1800 from opscode/sersut/chef#1634

DSCL User Provider Rewrite
Merge pull request #1811 from opscode/lcg/rhel-7-e2e

add rhel 7 e2e test
Add information on using Test Kitchen for E2E testing.
Create and test cookbook on Ubuntu 12.04