Add support for PUPPETLINT_FLAGS environment variable
Add support for PUPPETLINT_FLAGS environment variable

The environment variable PUPPETLINT_FLAGS can be used to provide additional
command line parameters to puppet-lint inside the pre-commit hook.

By default the following parameters are set:

* `--no-80chars-check`: Skip the 80chars check
* `--no-autoloader_layout-check`: Skip the autoloader_layout check

gini/puppet-git-hooks,anl/puppet-git-hooks,stumped2/puppet-hooks,bogdando/puppet-git-hooks,stumped2/puppet-hooks,gregf/chef-git-hooks,gini/puppet-git-hooks,anl/puppet-git-hooks,gregf/chef-git-hooks,bogdando/puppet-git-hooks