v1.6.0: JDK 11 support

Feature

• Support JDK 11 #51
  • thanks to @antfling for this excellent PR contribution ❤️
• add DnsCacheManipulator.listDnsNegativeCache method
• support DCM_AGENT_SUPRESS_EXCEPTION_STACK option
• [TOOL] add ls subcommand as alias of list
• [TOOL] deploy dcm tool to maven center

Improvement

• test code bad smell refactor/cleanup #52
  • thanks to @eas5 for this professional PR contribution ❤️
• add spotbugs-annotations and spotbugs-maven-plugin, and fix reported potential problems
• add more @Nonnull annotations
• code refactor/cleanup
  • rename fields/methods
  • fix warnings
  • improve error message
• upgrade dependencies and maven plugins
• add maven wrapper
• add .editorconfig

Documentation

• add DCM logo
• improve docs/javadoc
  • add download badge for dcm tool
  • fix broken links

CI/UT

• add Ubuntu on appveyor CI
• add coverallson appveyor CI
• improve unit test stability

Java Dns Cache Manipulator Library

• User Guide & Document
• java apidocs

maven dependency:

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>dns-cache-manipulator</artifactId>
    <version>1.6.0</version>
</dependency>

Already deploy to maven central repository.

Java Dns Cache Manipulator Tool

• User Guide & Document
• Download dcm-1.6.0.tar.gz