Setup Axios and Thunks

[dfagan2]

• introduces createReducer utility, that simplifies the reducer boilerplate per Redux documentation (https://redux.js.org/recipes/reducing-boilerplate#generating-reducers)
• sets up our axios instance, and demos a sample call within a redux action/reducer
• sets up our store with the thunk middleware, and demos a thunk within a sample action
• adds axios-mock-adapter and redux-mock-store (2 widely used libraries for testing async calls)
• creates a mocks and stubs file

[dfagan2]

@akrigline - feel free to add template blueprint updates to this PR as needed

[akrigline]

For record keeping, this solves #10