Make HTTP Requests to Github's API via RestTemplate

[mitchellirvin]

So during the hackathon, using RestTemplate resulted in some weird cert error when making a request to Github's public API. I spent like 4 hours trying to figure out why, and ended up using ProcessBuilder to execute a cURL request instead of using RestTemplate or the like.

- GithubRepoService.postForGithubRepoIssues should use a RestTemplate or something similar to execute an http request to the desired endpoint(s). This RestTemplate should probably be written in the config package.