Use internal snapshot repository for OSS snapshot packages [DI-154][5…

….5.z] (#209)

Backport of #207

- Use internal snapshot maven repository for getting OSS snapshot
distribution zip
- Do not produce brew packages for OSS snapshot as it would expose
password-protected urls

Fixes https://hazelcast.atlassian.net/browse/DI-154

Implemented similar like hazelcast-docker:
hazelcast/hazelcast-docker#774