Use flexbox to layout list

[quincyle]

This project uses semver, please check the scope of this pr:

• #patch# - backwards-compatible bug fix
• #minor# - adding functionality in a backwards-compatible manner
• #major# - incompatible API change

CHANGELOG

• Updated list layout strategy to use flexbox.

[sglanzer-deprecated]

This is fine, but I'm a little wary about making it a patch - the switch to 100% height on the list may burn some downstream consumers that based their CSS on the previous setup. Can we get confirmation of the impact of this on one of our major apps? If it's no impact, then go with the fix, otherwise go major

[coveralls]

Changes Unknown when pulling 1b41b72 on quincyle:develop into ** on ciena-frost:master**.

[coveralls]

Changes Unknown when pulling 1b41b72 on quincyle:develop into ** on ciena-frost:master**.

[quincyle]

@sglanzer You're right, it might have some unexpected impact on our downstream apps. Actually, this 100% on list root is not related the flexbox change, it is just something I feel we're missing previously (a default height for list), so I added it. I can just take it out for now and address later.

[coveralls]

Changes Unknown when pulling 1b41b72 on quincyle:develop into ** on ciena-frost:master**.

[coveralls]

Changes Unknown when pulling 27241a9 on quincyle:develop into ** on ciena-frost:master**.

[coveralls]

Changes Unknown when pulling 27241a9 on quincyle:develop into ** on ciena-frost:master**.

[coveralls]

Changes Unknown when pulling 42c77c2 on quincyle:develop into ** on ciena-frost:master**.

[sglanzer-deprecated]

Approved