feat: add new max_retries param to TwilioHttpClient

[msaelices]

Fixes #506

Fixes the #506 issue by retrying the failed connection.

I've seen something similar implemented in the Java version: https://github.com/twilio/twilio-java/blob/master/src/main/java/com/twilio/http/HttpClient.java

Checklist

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• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation about the functionality in the appropriate .md file
• I have added inline documentation to the code I modified

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