Test to ensure README is up-to-date

[mattldawson]

Currently there is a test in test/tutorial/test_README_example.cpp that tests whether the README example builds and runs, but there is no test to ensure that this code matches what is in the README, that the compile and run instructions in the README work, and that the results shown in the REAMDE match what is output. Add a test to check these.

Acceptance Criteria

• If the README example fails to build or run with the compile and run instructions shown in the README a test fails
• If the results shown in the README do not match the results of actually building and running the example shown following the instructions, a test fails.