HBCI-Sandbox build failure

Building the HBCI-Sandbox as described here (https://github.com/adorsys/open-banking-gateway/tree/develop/opba-protocols/sandboxes/hbci-sandbox) (variant with Java) causes a `DependencyResolutionException`.

Here is the error message:
```
[ERROR] Failed to execute goal on project hbci-sandbox: Could not resolve dependencies for project de.adorsys.opba:hbci-sandbox:jar:1.0.1-SNAPSHOT: Could not find artifact de.adorsys.opba:protocol-bpmn-shared:jar:1.0.1-SNAPSHOT in snapshots-repo (https://oss.sonatype.org/content/repositories/snapshots) -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException
```