Enable log FileHandlers per test function

[clacroix12]

Currently with our ocs-ci custom test runner we create a log FileHandler for every test case. We would like to replicate this behavior with pytest. One way of getting after this that sounds fairly straight forward is implementing a function level fixture that creates and removes the handlers for every test.

https://stackoverflow.com/questions/41400722/pytest-implementing-a-logfile-per-test-method

[vavuthu]

Assigning to myself.

[clacroix12]

#159