* hand down device serial into common entity
* fix platforms
* Revert "fix platforms"
This reverts commit 067af2b567.
* handle event loop issue
* hand in serial
* Revert "Revert "fix platforms""
This reverts commit 9bbb55ee6d.
* fix get serial call
* handle other exceptions
* also check device model for migration
* merge entity and device migration
* add test fixture without serial
* adjust test cases
* add dummy fixture
* remove commented code
* modify migration
* use continue
* break comment