Feature/import documents logging

[rkhaja]

I've added logging to the importDocuments method as well as created 2 additional JUnit tests.

[rashtao]

Thanks for your work @rkhaja !

Unfortunately we internally decided not to include for the moment the batch processing functionalities into the driver. This because batch processing has many caveats and it involves quite a broader set of requirements in order to be reliable and useful.
In order to achieve it you can for example use Spring Batch and configure it to use ArangoDB driver (or Spring Data ArangoDB).
If you are just interested in calling the driver in parallel from many threads, you can look at this example using the ArangoDB asynchronous driver:

https://github.com/arangodb/arangodb-java-driver-async/blob/1aea50201efc896121f213d52b736353dc1e2879/src/test/java/com/arangodb/example/document/ImportDocumentExample.java#L48

[rkhaja]

Ok. No problem.