Fix for creating comments for issue

Attempt to create a comment for issue results in "400 Bad Request"
(Problems parsing JSON) because request contains the comment body as
plain text.

In order to resolve the issue the Create and Update methods has been
changed to use BodyWrapper.
Merge pull request #262 from tpeczek/issues-comments-fix

Fix for creating/updating comments for issue
added failing test
VS2013 updates your project files to indicate which are test-runner friendly
the ids for events are not ints
Merge pull request #264 from octokit/263-ids-are-not-always-ints

EventsClient fix - ids are string, not ints
Expect anything for body since the test is about proving the earl is correct
Merge pull request #268 from ben-biddington/failing_tests

Expect anything for body since the test is about proving earl correctness (resolves #266)