Andreas Kodewitz

switched travis to trusty

1

Switched travis CI to Ubuntu Trusty and more recent version of R This should allow pull request #69 to pass CI

The readme section [Dependency Management](https://github.com/outerbounds/metaflow-card-notebook#dependency-management) contains a mistake. Line 5 of the code snippet should be ``` os.system(f"{sys.executable} -m pip ipykernel>=6.4.1 papermill>=2.3.3 nbconvert>=6.4.1 nbformat>=5.1.3") self.nb_options_dict = dict(input_path='nbflow.ipynb') ```