Kipoi

What's Changed
* Fixed sharding bug due to uneven splits of models into chunks by haimasree in https://github.com/kipoi/kipoi/pull/635
* Fixed build docs by haimasree in https://github.com/kipoi/kipoi/pull/636
* Better singularity logging by haimasree in https://github.com/kipoi/kipoi/pull/637


**Full Changelog**: https://github.com/kipoi/kipoi/compare/v0.7.3...v0.7.4

What's Changed
* Added singularity to kipoi-predict cli and added the tests
* Make singularity cli compatible with the multi container setup

Removed support for preprocessing tag in model.yamls
Updated variant effect prediction notebook with workflow eamples

* --vep cli option is deprecated
* References to kipoi-veff has been updated to kipoi-veff2 along with an updated notebook

- This version is now compatible with python 3.8 and 3.9
- A new model class is added to handle Tensorflow 2 models saved with tf.saved_model.save
- New groups of tests added to handle upgraded versions of Keras and Tensorflow 2

A bug was introduced in predict_generation in order to resolve an inconsistency between input data type and type of pytorch model parameters in tests. This has been fixed in this release.