#7: Add unit tests to OAuthDatasource
This MR
- sets up build infrastructure for running test in the gitlab ci
- sets up dependencies for various testing frameworks (junit4, io.mockk, io.strikt)
- Implements a JUnit4 runner to initialize MockK objects automatically
- adds unit tests for the OAuthDatasource
- refactors the underlying classes to achieve testability
Edited by Ryan Harg