Document how to deploy with args

* Populus Version: 2.0

http://populus.readthedocs.io/en/latest/deploy.html

### What was wrong?

The simple deployment example doesn't cover the usage of the deployment arguments.

Suggestion: Show a simple deployment Python script. This gives the users some flexibility to deploy and programmatically set constructor args or do further initialization calls.

#### Cute Animal Picture

```
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/\ /\
/ \ / \
```