Do not include junit as compile dependency

[claudia-maderthaner-infoniqa]

Describe the bug
Two subprojects (spring-content-azure-storage and spring-content-gcs) include junit as a compile dependency. Therefore, any project depending on any of these projects also includes junit as a transitive compile dependency.

To Reproduce
Include spring-content-azure-storage and/or spring-content-gcs as dependency in a build.

Expected behavior
junit should only be included as a test dependency.