Add integration tests for the service

[LeonidVas]

Add integration tests to check how to works rws with mkrepo. I think the tests should include:

• check pushing of deb/rpm/src.rpm packages
• check creation of metainformation
• check updating metainformation after pushing a new package
• check of metainformation update on request
• check metainformaiton update on start

The minio can be used as storage.