* Add nightly check and use specific version (currently the same) in PR checks
* wrong var name, whoops
* Create GH issue if nightly run fails
* need tokio feature for RpcClient; match dependency in root Cargo.toml.
* Ensure substrate command is properly cleaned up in the event of a panic, to prevent blocking
* increase retry limit again
* fmt
* Tweak text for nightly-run-failed issue template
* Run nightly-CI every 5mins for testing
* I clearly dont use cron enough
* Put back cron timings to 8am daily
* break a test
* revert nightly workflow again (doesnt run off master) and testing rust workflow
* more testing..
* undo testing things; seems to work
* tidy up; substrate url at top of both CI files