Timeout considered in milliseconds

## Goal
Allowing timeouts in milliseconds

## Need
For a high performance system, I needed a connection to elasticsearch, that couldn't last more that 250ms. If that case occurs, there's a fallback in memory. 

## Problem
There's no option for curlopt_timeout_ms developed.

## Solution
A new parameter on the connection that determines whether the timeout given should be considered as milliseconds or not.

## Tests
I run the tests and everything worked fine. 

## Feedback
Please, contact me in case of any doubt.