runInSequence = ( arrOfFnsReturningPromises ) => {
	return arrOfFnsReturningPromises.reduce(
		( lastStep, startNextStep ) => lastStep.then( startNextStep ),
		Promise.resolve()
	);
}
Helper function that takes in an array of functions that return promises,
then executes those functions sequentially to execute each action

@param {function[]} arrOfFnsReturningPromises An array of functions
@returns {Promise} A promise that will resolve once all the promises
returned by that function successfully complete