rabbitmq_reconnect_on_error parameter is useless

[cwjohnston]

Description of problem

The code added in #333 places a reconnect_on_error parameter under the rabbitmq configuration scope, e.g.

{
  "rabbitmq": {
    "reconnect_on_error": false,
  }
}

Per the documentation, this configuration parameter actually belongs under the transport configuration scope, e.g.

{
  "transport": {
    "name": "rabbitmq",
    "reconnect_on_error": true
  }
}

Further more, this parameter defaults to false, but Sensu defaults it to true as of version 0.18.

Proposed solution

The rabbitmq_reconnect_on_error parameter should be renamed to transport_reconnect_on_error and it's default value should be changed from false to true.

For the most part, references to rabbitmq_reconnect_on_error parameter, e.g. in rabbitmq manifest and sensu_rabbitmq_config provider, can be removed.

Code in the transport manifest should be changed so that transport.json is written regardless of the value of the transport_type parameter, and the boolean value of transport_reconnect_on_error should be used to influence the content of transport.json

[ghoneycutt]

There is existing work for this in PR #595

[ghoneycutt]

Released in v2.19.0