missing Tracelevel from v7.0.0 version

[karenbaldryan]

There is an inconsistency between these two files.

https://github.com/sohlich/elogrus/blob/v7/hook.go
https://github.com/sohlich/elogrus/blob/v7.0.0/hook.go

In function newHookFuncAndFireFunc(line:108), logrus.Tracelevel is missing from the list and therefore Trace logs are not getting pushed to elastic.