Gradle build fails: Unable to find method ‘org.gradle.api.tasks.testing.Test.getTestClassesDirs()Lorg/gradle/api/file/FileCollection;’

I had to change the distributionUrl in the gradle-wrapper.properties to distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip to get the build running again. This seems to be a similar problem Gradle sync failed: Unable to find method.