Support Managed Identities to connect to IoT Hub and Kafka

> Please provide us with the following information:
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### This issue is for a: (mark with an `x`)
```
- [ ] bug report -> please search issues before submitting
- [x] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce
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### Any log messages given by the failure
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### Expected/desired behavior
> Managed identities can be used to authenticate the Telemetry Simulator with IoT Hub and Kafka.

### OS and Version?
> Windows 7, 8 or 10. Linux (which distribution). macOS (Yosemite? El Capitan? Sierra?)

### Versions
>

### Mention any other details that might be useful

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