Added method to fetch project versions using GitHub API, removed hardcoded versions in tests.

Author: Onager

tests/download_helpers/github.py

@@ -85,7 +85,7 @@ def testGetDownloadURL(self):
     """Tests the GetDownloadURL functions."""
     download_helper = github.GitHubReleasesDownloadHelper(self._DOWNLOAD_URL)
 
-    project_version =  download_helper.GetLatestVersionWithAPI(None)
+    project_version = download_helper.GetLatestVersionWithAPI(None)
 
     download_url = download_helper.GetDownloadURL(
         self._PROJECT_NAME, project_version)