Disable ruby 2.1.5 automatically retrying idempotent http methods

While reviewing https://github.com/puppetlabs/puppet/pull/3107 I discovered that ruby 2.1.5 will automatically retry idempotent http methods, which includes GET, HEAD, PUT, DELETE if any of the following exceptions are raised:

      rescue Net::ReadTimeout, IOError, EOFError,

             Errno::ECONNRESET, Errno::ECONNABORTED, Errno::EPIPE,

             # avoid a dependency on OpenSSL

             defined?(OpenSSL::SSL) ? OpenSSL::SSL::SSLError : IOError,

             Timeout::Error => exception

According to the rfc7231:

A request method is considered "idempotent" if the intended effect on the server of multiple identical requests with that method is the same as the effect for a single such request.

The trouble is that we do not use PUT in an idempotent way. For example, each time we PUT a report, we store a *new* copy on disk and in puppetdb. In order to be idempotent, we would need to update the *one* report resource.

Normally that would not be a big deal. But when combined with ruby 2.1.5, it is possible that the agent can PUT a report, and the agent socket may timeout before the report processor finishes, or the load balancer may close the idle connection, e.g. PE-7326. In those cases ruby will catch the exception and retry the request, thankfully only once.

It does not appear ruby has a mechanism to disable this behavior...