0.18.0

• Use reproducible file order for plugin archives
• Eliminate usage of internal conventions API, using new Lazy Configuration approach instead; requires Gradle 4.4+
  • Technically, the APIs needed are available in Gradle 4.3, but there is a bug related to un-set Property instances in 4.3 and 4.3.1; see gradle/gradle#3879
• Cleaned up compatibility code for older versions of Gradle
• Built using Gradle 5.6.2
• Upgrade Spock from 1.2 to 1.3
• Upgrade Checkstyle from 6.1.1 to 8.23 and adjust rules used
• Upgrade Codenarc from 1.0 to 1.4 and adjust rules used
• Change source compatibility to 8
• Modernized for Java 8
• Built using Avro 1.9.1
• GenerateAvroProtocolTask now has a classpath property; defaults to the runtime configuration when the Avro plugin is applied
• GenerateAvroProtocolTask now properly declares the classpath as an input; fixes #86; thanks to RichSteele for the bug report
• Fix handling of default outputCharacterEncoding (use of system default character set to match Java compiler)
• Add support for generating getters that return Optional (#90); contribution from bspeakmon
• Add support for logicalTypeFactories and customConversions; fixes #92