Upgraded Twilio SDKs to latest version

Problem to solve

There are new versions of the Twilio SDKs. There should be no breaking changes in these upgrades according to the docs.

Proposal

• Upgrade Twilio SDK for Android from version 5.7.+ to 5.8.+
• Upgrade Twilio SDK for iOS from version 3.3 to 3.4

More information

• Changelog Android 5.8.0
• Changelog Android 5.8.1
• Changelog iOS 3.4.0
• Changelog iOS 3.4.1