Smooth pseudocode lines

To remove the border between pseudocode lines one can remove the margin-bottom from file `lib/odsaStyle-min.css`

```
.jsavcodeline {
  margin-bottom: 1px;
  font-size: 14px;
  line-height: 16px;
}
```
The exercises should be tested after this.

This change is present in jsav-exercise-recorder repo.