allow false as default arg to html page

[bdtomlin]

Purpose

Bug when using needs macro with boolean and false default value #978
Also added a few tests to keep things honest down the road.

Description

The source of the problem:

lucky/src/lucky/html_builder.cr

Line 52 in 33606a6

{% has_default = declaration.value || declaration.value == nil %}

This line accounts for nil, but not for false.

Checklist

• - An issue already exists detailing the issue/or feature request that this PR fixes
• - All specs are formatted with crystal tool format spec src
• - Inline documentation has been added and/or updated
• - Lucky builds on docker with ./script/setup
• - All builds and specs pass on docker with ./script/test

[paulcsmith]

Looks perfect! If you have time would you mind opening a PR for #804

It is along these same lines and would make it a lot nicer to use needs. But no pressure. I understand most of us are doing this in our free time :)

[bdtomlin]

@paulcsmith I'll definitely take a look at #804, if not today, within the next day or so.

[paulcsmith]

Awesome! Thanks @bdtomlin