Need Version Declaration [requirements.txt]

[acbuynak]

Noticed a dependency versioning issue that I would like to resolve and fix for this entire package. Setting up this issue to track progress.

Tasks:

• Identify all non-ROS depencies used
• Identify current version desired to use.
• Write requirements.txt file to ensure correct versioning use. Potentially include in a setup.py file.

[acbuynak]

OpenCV

Package name: cv2
Currently used versions:
4.2.0 requires format _, contours, _ = cv2.findContours()
3.2.0 requires format contours, _ = cv2.findContours()

Issue identified in commit 52d4ef5. The commit comment's root cause was incorrectly identified as a typo, real issue is that different versions of OpenCV handle this API call differently.

It is technically possible to write an if then, else type solution here, but I think we're better of picking a specific version and holding to it. I would suggest the newer version for longevity of the code.