This commit adds two new configuration settings for Smart Contract configuration:
- `interfaces` - Any Smart Contract that represent an interface or is used for inheritance
- `libraries` - Any Smart Contract that is used as a library
This makes the configuration less redundant in cases where otherwise the `deploy`
property has been set to `false`, such as:
```
deploy: {
Ownable: {
deploy: false
},
...
}
```
The above can now be done via:
```
interfaces: ['Ownable'],
deploy: {
...
}
```
Pascal Precht