Feature/v4 support

[ClaasBrueggemann]

Add Neo4J 4.0 support using the HTTP connector.
Bold is not supported.

[graphaware-bot]

Dear @ClaasBrueggemann,

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[graphaware-bot]

Dear @ClaasBrueggemann,

thank you very much for your Github contributions to GraphAware's
software. In order for us to be able to accept and keep your
contributions, we would like to ask you to download, fill in, sign, and send us
a photo / scanned copy of the attached Contributor License Agreement to cla@graphaware.com .

Thank you very much in advance,

Kind Regards,

The GraphAware Team

[ikwattro]

@ClaasBrueggemann Not sure it is really adding any support to Neo4j 4 ?

[ClaasBrueggemann]

@ikwattro It will not support multi databases and will still use the old api endpoints, but at least you can connect to the default database and run queries. Full support needs more work.

[patrickkusebauch]

@ClaasBrueggemann Hey, I am really interested in having multi-database support. Is there any way I can help to make it happen? I am even willing to write the PR if necessary, but it seems inevitable that this PR is merged first.

[ClaasBrueggemann]

@patrickkusebauch Hey, you can have a look at my forked repo:
https://github.com/ClaasBrueggemann/neo4j-php-client

Especiallythe last commit(ClaasBrueggemann@beb5963) will be interesting for you. It adds
the requested multidatabase support.

The changes i made should be considered as a quick and dirty solution and can't be merged right away, because i copied the SessionInterface.php from another composer package to the main project and added a new method called useDatabase.

Changing the SessionInterface should be done in the respective repository (https://github.com/graphaware/neo4j-php-commons). In this case somebody needs to update the bold connector, because it's using this interface too. (or use a different version tag)