Add missing test dependency

[jacobperron]

I'm hope this will fix an issue with CI.

[pmusau17]

Built this on ros2 foxy. All tests passed. One warning.

Warning: the matrix subclass is not the recommended way to represent matrices or deal with linear algebra (see https://docs.scipy.org/doc/numpy/user/numpy-for-matlab-users.html). Please adjust your code to use regular ndarray.
-- Docs: https://docs.pytest.org/en/latest/warnings.html

[JWhitleyWork]

@jacobperron It looks like several of the stereo_image_proc tests timed out.

[pmusau17]

@jacobperron @JWhitleyWork I have a fix for the timeout here

[jacobperron]

Rebased.