Update the golang Azure samples to use go modules

> 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
- [x] 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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Install with latest go language version (that supports go module)

### Any log messages given by the failure
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### Expected/desired behavior
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Expected to import/use the sample code with go module support for the consuming any of the Azure features

### OS and Version?
> Windows 7, 8 or 10. Linux (which distribution). macOS (Yosemite? El Capitan? Sierra?)
Any of the OS with their versions
### Versions
>

### Mention any other details that might be useful
Not really sure how to repro this issue. I will need to create a sample which tries to use Azure libraries as go modules (which don't exist right now). The rest of the libraries would be possible to import.
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