Create list of tests to make, ordered by priority

[jkbhagatio]

• Test for processExperiment
• Test for loadDatafile
• Test for selectTrials

[jkbhagatio]

@lewool We should think about which high priority tests we want to create for the repo. Feel free to add functions you think are important to create tests for to the list I've created in the issue body (so far just processExperiment). Then we can create these tests together!