Verify that sha512 files are correctly published during next release

[valdar]

See https://infra.apache.org/release-distribution#sigs-and-sums and this commit: 94246b4

[valdar]

They were not published during 0.2.0 release. These piece of work from INFRA is needed: https://issues.apache.org/jira/browse/INFRA-14923

[valdar]

It seems that https://issues.apache.org/jira/browse/INFRA-14923 is now resolved, so the next release (0.3.0) should be the one to verify this 🤞.

[valdar]

Unfortunately, this wasn't enough 😞 conversation is continuing in https://issues.apache.org/jira/browse/MINSTALL-138 and https://issues.apache.org/jira/browse/MRESOLVER-56

[valdar]

This is not needed anymore after clarification in the previous mentioned issues discussions with ASF infra.