Description of problem:
Puppet class is created multiple times when content views with the same class
are published in parallel.

Steps to Reproduce:
1. On a clean instance, prepare 2 content views with the same puppet class:

hammer --output csv organization create --name clash_a
hammer --output csv organization create --name clash_b
hammer --output csv product create --description description --label clash_product_a_label --name clash_product_a --organization-id 3
hammer --output csv product create --description description --label clash_product_b_label --name clash_product_b --organization-id 4
hammer --output csv repository create --content-type puppet --name puppet_clash_repo_a --product-id 245 --publish-via-http true --url="http://puppetmodules.example.com/bagoftricks" 
hammer --output csv repository create --content-type puppet --name puppet_clash_repo_b --product-id 246 --publish-via-http true --url="http://puppetmodules.example.com/bagoftricks" 
hammer --output csv repository synchronize --id 10
hammer --output csv repository synchronize --id 11
hammer --output csv content-view create --name clash_cv_a --organization-id 3
hammer --output csv content-view create --name clash_cv_b --organization-id 4
hammer --output csv content-view puppet-module add --author robottelo --name generic_1 --content-view-id 5
hammer --output csv content-view puppet-module add --author robottelo --name generic_1 --content-view-id 6

2. publish content views in parallel, I used hammer from 2 different terminals

3. go to Configure -> Puppet Classes, you should see duplicate entries, each in different environment

Actual results
Publishing in parallel bypasses the Rails validations and creates duplicates. Puppet classes with the same name break 'hammer puppet-class info --name' command.

Expected results:
No duplicates should exist.