* add a self.temp_dir in setUp and remove in teraDown
* be consistent in order of (expected, actual) args
* assert the complete exception error line
Related-Change: I289d3e9b6fe14159925786732ad748acd0459812
Change-Id: I185c8cd55db6df593bb3304c54c5160c1f662b86
Signed-off-by: Alistair Coles <alistairncoles@gmail.com>