Please make sure to check the following requirements before creating a pull request:
* [ ] All pull requests must be to the [develop branch](https://github.com/almende/vis/tree/develop). Pull requests to the `master` branch will be closed!
* [ ] Make sure your changes are based on the latest version of the [develop branch](https://github.com/almende/vis/tree/develop). (Use e.g. `git fetch && git rebase origin develop` to update you feature branch).
* [ ] Make sure your changes are based on the latest version of the [develop branch](https://github.com/almende/vis/tree/develop). (Use e.g. `git fetch && git rebase origin develop` to update your feature branch).
* [ ] Provide an additional or update an example to demonstrate your changes or new features.
* [ ] Update the documentation if you introduced new behavior or changed existing behavior.
* [ ] Reference issue numbers of issues that your pull request addresses. (If you write something like `fixes #1781` in your git commit message this issue gets closed automatically by merging your pull request).