Replace client

[tienvx]

• Use Github Actions
  • Remove StyleCI
  • Remove Travis
  • Remove build files
    • install-jdk8.sh
    • install-neo.sh
  • Use PHP-CS-FIXER
    • Use rules
      • PSR12
      • Symfony
• PHP updated to >= 8.0
  • Add type hints to all parameters. Removed all annotations related to type hints (by PHP-CS-FIXER)
• Replace graphaware/neo4j-php-client by laudis/neo4j-php-client
• Remove
  • psr/log
  • symfony/event-dispatcher
• Removed classes that I think not used, please tell me if I'm wrong
  • GraphAware\Reco4PHP\Common\NodeSet
  • GraphAware\Reco4PHP\Cypher\Query
  • GraphAware\Reco4PHP\Post\BasePostProcessor
  • GraphAware\Reco4PHP\Result\PartialScore
  • GraphAware\Reco4PHP\Result\Reason
  • GraphAware\Reco4PHP\Transactional\BaseCypherAware
  • GraphAware\Reco4PHP\Transactional\CypherAware
  • GraphAware\Reco4PHP\Util\NodeProxy
• Update syntax in README.md
  • Cypher version 4.4
  • PHP 8.0
• Add UPGRADE.md

Questions:

• Do we support PHP 7.4? It will be not supported in about 1 month from now
• Not sure we want to keep:
  • _algo-examples
  • _demo
  • example.php
• Not sure tests/Example/* is in correct place. Should we move it outside? e.g. _example?
• Should we create test.php to run example in tests/Example? Currently it's missing.
• Or reorganize them to:

_example
│
└───Github
│   │    example.php
│   │
│   └─src
│       │   FollowedByFollowers.php 
│       │   PenalizeTooMuchFollowers.php
│       │   RecommendationEngine.php
│       │   SameContribution.php
│   
└───Movie
│   │    test.php
│   │
│   └─src
│       │   ExampleRecommenderService.php
│       │   ExampleRecommendationEngine.php
│       │   Discovery
│       │   Filter
│       │   PostProcessing
│   
└───Algo
│   │    cosine-similarity.php

• Do you want to split this pull request to smaller pull requests?
• I assume unit tests are missing for some classes. We will add them later?