* Start adding merge tests
* Expose MockExecutionLayer
* Add mock_execution_layer to BeaconChainHarness
* Progress with merge test
* Return more detailed errors with gas limit issues
* Use a better gas limit in block gen
* Ensure TTD is met in block gen
* Fix basic_merge tests
* Start geth testing
* Fix conflicts after rebase
* Remove geth tests
* Improve merge test
* Address clippy lints
* Make pow block gen a pure function
* Add working new test, breaking existing test
* Fix test names
* Add should_panic
* Don't run merge tests in debug
* Detect a tokio runtime when starting MockServer
* Fix clippy lint, include merge tests
