Bug with v1.0.3 and Session Handling when running Tests

[justinyost]

If an Integration Test setups Session Data using the Session Proxy, this data is no longer available in v1.0.3

http://book.cakephp.org/3.0/en/development/testing.html#setting-up-the-request

Due to the session not being registered as started and hence starting the session which clears out the session data for it being a CLI instance of Session: https://github.com/cakephp/cakephp/blob/master/src/Network/Session.php#L311