Minor updates to 0.3.1 software
* New: Additional Jupyter notebook for particles filtering, `cryoDRGN_filtering.ipynb`
* New: `cryodrgn view_config`
* Fix: Compatibility and deprecation fixes with pytorch 1.7 (29), scipy (39), and seaborn (3111efdc4c147716fd34e6a860ddf6d512f17fdb)
* Updated: More functionality for converting to starfiles with `write_starfile.py` (44)
* Performance improvements to `cryodrgn eval_vol` and a minor fix for a corner case (33)
* Note: The logged KL divergence in stdout is no longer scaled by beta, however the default objective is identical