I was implemented, "install_chef_client" option for AmazonLinux.

Hi there

I was implemented `install_chef_client` option for AmazonLinux.

- Install the Chef-client when generating the EC2 instance.
- The solution is to comment out the setting of the `Defaults requiretty` of `/etc/sudoers`, the problem of `sudo mkdir -p` in `AWS::Action::SyncFolders#call` fails.

- `user_data` option will be overwritten for this option.
If the `user_data` option and `install_chef_client` option is enabled at the same time, it will display a warning to the user.