fix: generate valid dev private key

[jbolda]

Motivation

It appears that calls to the simulated GitHub endpoint were failing. However, the octokit instance was failing at creation due to an issue with the private key that was generated for testing purposes. Despite as such, the tests were still passing.

Modifications

• Adjusted the private key to output as single line string. octokit could then make a valid instance.
• Removed the code paths which used test as dependency as they were not required.
• Added a few new org/repo combinations that would be used now that calls were being made to the GitHub simulator.