Fix bug for #2117 - http url not working

[fc]

(whoops branch should've been issue-2117-http-url-not-working...)

Summary

0. This PR will resolve issue Error downloading git repo over HTTP without a commit hash #2117.
1. It will upgrade an HTTP URL to HTTPS and see if that works then fallback to using HTTP if it fails.
2. It will test an HTTPS URL too and verify that the git repos exists
3. Fix and rewrite the broken tests

Test plan

The cause of the bug was having a project dependency which itself depended on an HTTP repos.

{
  "name": "yarn-test",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "pm2": "^1.1.3"
  }
}

Running a yarn install on the above would trigger this error

error Refusing to download the git repo http://ikt.pm2.io/ikt.git over HTTP without a commit hash

HTTPS is not valid for that domain since they have an Invalid certificate chain (refer to #2117 for details).