Release v0.4.0

What's changed

• Fix duplicate plugins in plugin list command (#218) @zymap
• Update version file (#217) @zymap
• Update release process to include the plugins (#214) @zymap
• Add default plugins dir to check (#215) @zymap
• Fix wrong CI version (#213) @zymap
• Add v0.3.0 web site on README (#212) @wolfstudy
• Add security tool as a plugin to pulsarctl (#211) @sijie
• Support list plugins command (#207) @zymap
• [Issue 180] Make error log use stderr (#206) @zymap
• Separate functions related tests to a new CI (#210) @zymap
• [Issue 183] Fixes can not parse the destination_auth (#204) @zymap
• [Issue 185] Fix pulsarctl schemas get --version 0 produces incorrect results (#205) @zymap
• Using plugin handler to add other pulsar related tools (#188) @zymap
• Add update homebrew formula in the release process (#200) @zymap
• Add RetentionPolicy parsing (#201) @rivernate
• Change NameSpaceAuth to be an [] of AuthAction (#202) @rivernate
• [issue:182] get-function-assignments has incorrect output (#199) @wolfstudy
• [issue:197]Check Nil interface the right way (#198) @wolfstudy
• Rework auth and add pulsar client conf (#196) @rivernate
• Automatically use a context when it is added (#193) @wolfstudy
• [issue-126] Add information about output formats to developer guide (#195) @EronWright
• Fix maven broken link (#192) @wolfstudy