Storm UT fails on supervisor test in Windows (0.10.x)

supervisor UTs seem not handle file path delimeter properly so it fails on Windows consistently but no problem on other OS.

I can easily reproduce this from 0.10.x-branch, but I can't reproduce this from master or 1.x-branch since there're other tests which crash whole tests so that test phase couldn't even reach supervisor-test.

For 1.x-branch, blobstore crashes test phase on Windows. I'll link relevant issue.
For master, I'm not sure what issues lay here.