Remove deprecated settings from Gradle build files

[climategadgets]

Current Gradle build issues this warning:

Deprecated Gradle features were used in this build, making it incompatible with Gradle 5.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/4.9/userguide/command_line_interface.html#sec:command_line_warnings

[climategadgets]

Fixed somewhere down the road.