(PE-3401) Addressed README.md and test feedback from pull request

This commit corrects a reference to the `overrides` parameter in the
README.md.

This commit also contains several test updates:

- Removed unnecessary Service1 service protocol.
- Removed unnecessary str function invocations from one test for
  strings that didn't involve concatenation.
- Adjusted testing string on an SSL certificate settings override test
  to better describe the purpose of the test.
- Replaced `second-override-throws?` variable with
  `second-override-result` variable in second override attempt test to
  better indicate what the variable value could hold.
- Removed unused require statement.