This PR introduces Gradle 5 support for pygradle and drops Gradle 4 support by changing gradle-wrapper and Readme.md files. Other changes are done to make code compatible with the new plugin:
DependencyOrderTest.groovy was changed because the new groovy compiler bundled with new gradle was getting name collisions on affected statements.
ProxyDetector.groovy had codenarc code style violations.
com.github.johnrengelman.shadow plugin version was updated because it starts to support Gradle 5 only with version 5+
PyTestTask.groovy was changed to replace old removed internal APIs with new public replacement.
All other files were modified to fix the integration test failure that was caused by EditablePythonAbiContainer. EditablePythonAbiContainer is an extension, and you cannot use the extension as a serializable task input in Gradle 5, because of Gradle injects some additional information in extension objects. The solution of the problem was to create a copy of the extension object that wouldn't have this information in it.
This PR introduces Gradle 5 support for pygradle and drops Gradle 4 support by changing gradle-wrapper and Readme.md files. Other changes are done to make code compatible with the new plugin: