Whitelisted variables return null if not set

What's Changed

• feature: whitelisted variables return null if not set by @g105b in #145
• Upgrade to GitHub-native Dependabot by @dependabot-preview in #56
• Using assertSame to assert expected strictly by @peter279k in #57
• build: hard dependencies by @g105b in #134
• maintenance: dependabot by @g105b in #143

A lot of dependabot bumps

• Bump phpunit/phpunit from 8.1.6 to 8.2.0 by @dependabot-preview in #22
• Bump phpunit/phpunit from 8.2.0 to 8.2.1 by @dependabot-preview in #23
• Bump phpunit/phpunit from 8.2.1 to 8.2.2 by @dependabot-preview in #24
• Bump phpunit/phpunit from 8.2.3 to 8.2.5 by @dependabot-preview in #27
• Bump phpunit/phpunit from 8.2.5 to 8.3.5 by @dependabot-preview in #31
• Bump phpunit/phpunit from 8.3.5 to 8.4.2 by @dependabot-preview in #34
• Bump phpunit/phpunit from 8.4.2 to 8.5.3 by @dependabot-preview in #39

New Contributors

• @peter279k made their first contribution in #57
• @g105b made their first contribution in #134

Full Changelog: v1.0.0...v1.1.0