Fix example programs

Here are fixes to a few runtime errors that I encountered while attempting to run the example programs. 

Regarding 057560c, there is perhaps an ambiguity in the API. Should the call to the utility function `render(...)` be

```python
bashes.render(...)
```
or 
```python
bashes.utility.render(...)
```

?

If the former is intended, then the line in `bashes/__init__.py`

```python
import utility
```

should be changed to:

```python
from utility import *
```