6.14.1: `flex` uses unmaintained `validate-emai` module

[kloczek]

flex/setup.py

Lines 28 to 31 in 14b405e

	install_requires=[
	"six>=1.7.3",
	"PyYAML>=3.11",
	"validate-email>=1.2",

validate-emai is unmaintained since 2015 https://github.com/syrusakbary/validate_email/

[nieder]

See #235 for update to alternative