Deepcell-tracking

Features

- Updated `tracking.py` to consume data from dictionaries instead of lists, as required by TensorFlow 2. This is a breaking change.

Features

* Migrate CI/CD from TravisCI to GitHub Actions. (32)
* Replaced `opencv-python` with `opencv-python-headless` for faster builds and fewer dependencies. (33)

Bugfixes

- Pin OpenCV <= 3.4.9.31 for wider Python support. (31)

The 0.2.5 release makes a few small code improvements such as:

* Adding an inner function `_track_frame` to be called in the frame loop inside `track_cells`.

* Improving the consistency of method/class names across all files.

* Adds tests for the I/O utility functions, and improves code coverage to >80%.

This release addresses the ISBI text file related bugs and resolves the warnings generated by 16.

Migrate ISBI utility functions from `deepcell-tf` to `deepcell-tracking` and update deprecated `networkx` functions to enable compatibility with `networkx>=2.4`.