SOPFLOW Python Tests re-visit (functionality vs unit tests)

[cameronrutherford]

Issue type

• Bug

Relates to

• SOPFLOW

Summary

From this thread on #131, it is clear that SOPFLOW tests run the entire application many times, however these are only functionality tests. We should also ensure unit tests.

There is a comment in the source code that mentions the inability to do this without calling sopflow.setup() or else our destructor segfaults. We should also either:

• Fix this issue in the destructor, and make sure the correct memory is allocated / freed and the bug is squashed
• Document this thoroughly, explain why, and make sure users are aware

cc #140 as well since a similar issue was seen there according to @jaelynlitz and @Jayapreethi