Updated ruby requirement to 3.0

[Nuzair46]

Description

Updated ruby minimum version requirement to 3.0

Related Issue

closes #62

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[Nuzair46]

@afrase Please merge this as this allow release action to perform.

[afrase]

@Nuzair46 Can you update Zerobounce::VERSION. I published 0.3.0 to rubygems.org already.