Upgrade gradle version.
MODIFY
examples/dropwizard-mongo-client/gradle/wrapper/gradle-wrapper.jar
examples/dropwizard-mongo-client/gradle/wrapper/gradle-wrapper.jar
Binary files a/examples/dropwizard-mongo-client/gradle/wrapper/gradle-wrapper.jar and b/examples/dropwizard-mongo-client/gradle/wrapper/gradle-wrapper.jar differ

MODIFY
examples/dropwizard-mongo-client/gradle/wrapper/gradle-wrapper.properties
examples/dropwizard-mongo-client/gradle/wrapper/gradle-wrapper.properties
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.7-bin.zip
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-bin.zip

MODIFY
examples/rest-spark/gradle/wrapper/gradle-wrapper.jar
examples/rest-spark/gradle/wrapper/gradle-wrapper.jar
Binary files a/examples/rest-spark/gradle/wrapper/gradle-wrapper.jar and b/examples/rest-spark/gradle/wrapper/gradle-wrapper.jar differ

MODIFY
examples/rest-spark/gradle/wrapper/gradle-wrapper.properties
examples/rest-spark/gradle/wrapper/gradle-wrapper.properties
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.7-bin.zip
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-bin.zip

MODIFY
examples/spring-boot-jdbc-redis/gradle/wrapper/gradle-wrapper.jar
examples/spring-boot-jdbc-redis/gradle/wrapper/gradle-wrapper.jar
Binary files a/examples/spring-boot-jdbc-redis/gradle/wrapper/gradle-wrapper.jar and b/examples/spring-boot-jdbc-redis/gradle/wrapper/gradle-wrapper.jar differ

MODIFY
examples/spring-boot-jdbc-redis/gradle/wrapper/gradle-wrapper.properties
examples/spring-boot-jdbc-redis/gradle/wrapper/gradle-wrapper.properties
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.7-bin.zip
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-bin.zip

MODIFY
gradle/wrapper/gradle-wrapper.jar
gradle/wrapper/gradle-wrapper.jar
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ

MODIFY
gradle/wrapper/gradle-wrapper.properties
gradle/wrapper/gradle-wrapper.properties
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.7-bin.zip
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-bin.zip

Upgrade gradle version.