merge release 1.1.0p2 work

[f34rdotcom]

• Add Travis platformio build test.
• Fix / improve Twilio error handling and fix missing switch causing the Twilio component to stop working and coredump. Thanks to the new coredump routine it was much easier to track down the fault after the fact.
• Cleanup and organize sdkconfig.defaults. It "should" build again from build clean. Need others to try and test so I get some feedback on build issues. If possible add some way to cross compile build on commit with Travis CI.
• Small changes to default ad2iot.ini config file to show use of more virtual switches for events.
• Fix building stsdk. TODO: Fix FTPD and complete onboarding test.