Update release notes for 0.3.5
Fix path to SolutionInfo.cs
Remove preview accept media type

This media type is only needed IF You want to make retrieving statuses
available at the endpoint /repos/:owner/:repo/commits/:ref/statuses. But
we're not doing that here.
Fix broken unit test
Merge pull request #515 from octokit/release

Update release notes for 0.3.5