Adding explicit import of mock.patch as bugfix

[kjjarvis]

This PR addresses a bug in using the 'mock' attribute of unittest by explicitly importing mock in each test that uses this

[github-actions[bot]]

Thank you for opening this PR. Each PR into dev requires a code review. For the code review, look at the following:

• [ ] Reviewer (someone other than author) should look for bugs, efficiency, readability, testing, and coverage in examples (if relevant).
• [ ] Ensure that each PR adding a new feature should include a test verifying that feature.
• [ ] All errors from static analysis must be resolved.
• [ ] Review the test coverage reports (if there is a change) - will be added as comment on PR if there is a change
• [ ] Review the software benchmarking results (if there is a change) - will be added as comment on PR
• [ ] Any added dependencies are included in requirements.txt, setup.py, and dev_guide.rst (this document)
• [ ] All warnings from static analysis must be reviewed and resolved - if deemed appropriate.

[github-actions[bot]]

Benchmarking Results From:	Test	Time (s)
import main	0.1766527
import thrown object	0.6116358000000002
model initialization	0.18082779999999987
set noise	0.8325385999999999
simulate	0.4348478
simulate with saving	1.3492655000000005
simulate with saving, dt	1.4616660999999995
simulate with printing results, dt	1.8702232999999993
Plot results	23.089373900000002
Metrics	0.04467750000000592
Surrogate Model Generation	2.510675599999999
surrogate sim	1.8509103999999965
surrogate sim, dt	4.475918800000002

To:	Test	Time (s)
import main	0.17432310000000006
import thrown object	0.6893423000000001
model initialization	0.18304890000000018
set noise	0.8234494000000003
simulate	0.4621934999999997
simulate with saving	1.4764814999999998
simulate with saving, dt	1.6174641999999997
simulate with printing results, dt	1.9289454000000008
Plot results	23.043684700000004
Metrics	0.04867800000000244
Surrogate Model Generation	2.478695000000002
surrogate sim	1.8529102999999978
surrogate sim, dt	4.581453000000003