Remove WebServerListener

[ddeboer]

https://github.com/FriendsOfSymfony/FOSHttpCacheBundle/blob/master/phpunit.xml.dist#L32 is a leftover. We should either remove it, or add integration tests against a web server. Originally, I preferred to have all integration tests in the library instead of the bundle. May may, however, want to the the user context and the ProxyTestCase (e.g., getResponse()) against a real setup. This comes at the cost of more fragile tests, I guess.

[dbu]

lets remove it for 1.0 and re-add it when we actually need it.