Unable to send 1.4MB PDF due to not being able to pass configurations to the HTTP adapter

[RStrydom]

We have recently hit a roadblock not being able to send PDFs as attachments as we kept hitting the time-out of CURL - set to a default of 10 seconds. We tried setting the time-out to something else but it never seemed to work and always used the 10 seconds. After some investigation we realised that the configuration of the HTTP adapter is not passed through when instantiating a new instance of Sparkpost.
We are currently setting up a pull request to fix this issue although this does depend on the use of Ivory and would probably not be applicable when Sparkpost moves over to httplug.

[RStrydom]

Haven't gotten the time yet to roll the pull request - for anyone that has this issue and needs to resolve this urgently, see the change we made below (This change fails on the unit tests)
Edit: vendor/sparkpost/php-sparkpost/lib/SparkPost/SparkPost.php
Line: 99
$httpConfig = ($this->httpAdapter->getConfiguration()) ? $this->httpAdapter->getConfiguration() : new Configuration();