Spencer Ochs

Add unit tests to arrival time algorithms

3

Add tests to "data science" functions to allow newcomers to get better grasp of what functions are doing, shape of data input/output, and to allow easier changing/fixing of functions. Functions...

1. Determine set of queries to test against when making changes to the API. 2. Create suite of tests using [snapshot testing](https://docs.graphene-python.org/en/latest/testing/) Example of tests: https://github.com/graphql-python/graphene/tree/master/examples/starwars/tests