Add a default timeout to curl and a custom log dir

[dbhynds]

We've been using a fork of this package for a while. I figured it's worth opening up a PR for the changes. This PR:

• Adds a default timeout to CURL requests to prevent long-running requests from blocking the thread
• Adds the ability to specify a custom logs directory on the file emitter

For the timeout, we had issues where the service being called by the CurlEmitter was experiencing high latency. This is a resiliency measure that allows us to terminate slow requests and avoid high latency in another system from causing latency issues in our application.

[snowplowcla]

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[dbhynds]

I signed it!

[snowplowcla]

Confirmed! @dbhynds has signed the Contributor License Agreement. Thanks so much.

[matus-tomlein]

Thanks for the contribution @dbhynds! It looks good, but I would like to make a small change to keep the default timeout for curl while making it configurable.

I will cherry pick your commit and make the changes. Thanks again for the PR!