Test the base_buildpack class

The existing base_buildpack implementation was not tested and missing a
'names' method used to output an error message.  This change adds in the
missing code and adds new examples to the base_buildpack spec.

[#71229794]
Merge branch 'cgfrost-71229794-test_base_buildpack'
Improve CheckAPIDocTask

Previously the CheckAPIDocTask was written in a naive way and was
untested.  Using the Rubocop and RSpec Rake tasks as a pattern, the
implementation was improved to allow more configuration flexibility
and testability.  Finally the testing of the task was improved.

[#71229830]
Merge 71229830-test-check_api_doc to master

[Completes #71229830]