More complete integrations tests

[rvanderwal-newrelic]

We have coverage in our unit tests, but feel like the functional/integration side of testing is lacking.

We have some level of integration tests in our examples for our integrations and the main agent, but running those tests has been a manual process. Devise a good way to automate this process, and perhaps write other examples or integration tests that more closely resemble real-world use of the Go Agent.