With the addition of the num_engine_workers param in puppet-heat, we
can now wire the HeatWorkers parameter to also set that value, as
with the other workers.
Change-Id: I169b648737f797ccd45d12b66705d111e7b95bb7
Depends-On: I53a4333ca16df516294c733f85546c0b0a6a0b88
heat::api_cloudwatch::workers: {get_input: heat_workers}
heat::api_cfn::bind_host: {get_input: heat_api_network}
heat::api_cfn::workers: {get_input: heat_workers}
+ heat::engine::num_engine_workers: {get_input: heat_workers}
heat::database_connection: {get_input: heat_dsn}
heat::debug: {get_input: debug}
heat::db::mysql::password: {get_input: heat_password}