DDC-2047: [GH-456] Optimize autoload prefix in composer.json

[doctrinebot]

Jira issue originally created by user @beberlei:

This issue is created automatically through a Github pull request on behalf of Slamdunk:

Url: #456

Message:

By having more specific autoload prefixes it is possible to reduce the number of stat calls made.

[doctrinebot]

Comment created by @beberlei:

A related Github Pull-Request [GH-456] was closed
#456

[doctrinebot]

Issue was closed with resolution "Fixed"

[doctrinebot]

Comment created by @doctrinebot:

A related Github Pull-Request [GH-456] was closed:
doctrine/dbal#456