Create tests for tensor generator

[StevenSong]

What
Create tests for tensor generator before rewrite. #353

Why
Test Driven Dev

How
new tests in test_tensor_generators.py

Acceptance Criteria

• test to visit all paths N times before the N+1 times
• test that stats reported are correct, tensors presented = good tensors + bad tensors

[StevenSong]

@ndiamant @lucidtronix @erikr feel free to add to the issue with tests that should be implemented, will prob be easier to update after meeting to discuss