Apache Release 2.2.1

What's Changed

• Fixed issue #178: By @leerho in #181
• Updated spotbugs and fixed all the warnings. By @leerho in #182
• Fixed some checkstyle configuration errors. By @leerho in #183
• The pom file in the ds-memory-java11 branch used indents of 4 instead of 2. By @leerho in #185
• updates to POM files. By @leerho in #184
• Fix Java 11 build/compile problem. By @leerho in #187

This release is restricted to compile and run on Java 8 and 11. Based on other users experiences, it will run (but not compile) on Java 17 as long as one doesn't attempt to allocate off-heap memory using the allocateDirect(...) call. But we don't officially support this limited configuration.

Full Changelog: 2.2.0...2.2.1