TempDirs are deleted when they go out of scope #61
Description
https://docs.rs/tempfile/latest/tempfile/struct.TempDir.html
The TempDir type creates a directory on the file system that is deleted once it goes out of scope.
Temporary directories created for tests go out of scope before the test finishes. This causes the directory to be deleted if rocksdb does not have any open file handles.
This issue doesn't currently seem to cause problems probably because rocksdb keeps the file handles open to the data directory. However this is breaking when I'm trying to use rocksdb checkpoints in tests.