[issue-143] Update Java 11 and Hadoop 3.3 and latest Pravega

[crazyzhou]

Change log description

• Update Java 11 and Hadoop 3.3 and latest Pravega

Purpose of the change Fixes #143

What the code does

• Update Java 11
  • Fix checkstyle
  • Update gradle to 6.5.1
  • Fix deprecated use of Class.newInstance() to use Class.getDeclaredConstructor().newInstance()
• Update Hadoop 3.3
• Update latest 0.9 Pravega dependency and submodule to commit 039c4a3
  • Change the package of Credentials

How to verify it ./gradlew clean build passes