* Minimum hacks required to run cypress tests with dendrite
* Remove wget hack since dendrite containers now have curl
* Add basic dendritedocker plugin & hack into login spec for testing
* Add generic HomeserverInstance interface
* Add env var to configure which homeserver to use
* Remove synapse specific homeserver support api
* Update the rest of the tests to use HomeserverInstance
* Update cypress docs to reference new homeserver abstraction
* Fix formatting issues
* Change dendrite to use main branch container
