Codebase modernization: parent issue

[thedotedge]

• Set target PHP compatibility: 8.x
• Update dependencies to latest
• Update PHPUnit https://github.com/webimpress/phpunit-migration
• Remove deprecations and warnings
• Internalize https://github.com/wa0x6e/ResqueStatus into this repo
• Internalize https://github.com/wa0x6e/php-resque-ex-scheduler into this repo
• Internalize https://github.com/wa0x6e/php-resque-ex into this repo
• Cleanup and update readme
• Set up CI builds (CircleCI or Travis?)
• Define release process
• Release 2.0.0
• Remove Redisent

[TheMY3]

Update PHPUnit
Set up CI builds (CircleCI or Travis?)

Released here - #4

Set target PHP compatibility: 8.x
Update dependencies to latest
Remove deprecations and warnings (Except one test)

Released here - #5

[TheMY3]

Internalize wa0x6e/ResqueStatus into this repo

Released here - #6

[TheMY3]

Internalize https://github.com/wa0x6e/php-resque-ex-scheduler into this repo
Internalize https://github.com/wa0x6e/php-resque-ex into this repo

Released here - #8
Schedule will not be supported

Cleanup and update readme

Released here - #9