Remediate High pyyaml vulnerability

[Lilalamar]

Snyk reports the following High severity vulnerability in HumanCellAtlas/data-store. Please remediate by the end of Q2 Milestone 2.

Description
pyyaml

Suggested Remediation
Upgrade pyyaml to version 5.3.1 or higher.

Details
pyyaml is a YAML parser and emitter for Python. Affected versions of this package are vulnerable to Arbitrary Code Execution. It is susceptible to arbitrary code execution when it processes untrusted YAML files through the full_load method or with the FullLoader loader. Applications that use the library to process untrusted input may be vulnerable to this flaw. An attacker could use this flaw to execute arbitrary code on the system by abusing the python/object/new constructor.