Upgrade to Gradle 4.8

build.gradle

@@ -59,7 +59,7 @@ buildscript {
     ext.h2_version = '1.4.197' // Update docs if renamed or removed.
     ext.postgresql_version = '42.1.4'
     ext.rxjava_version = '1.2.4'
-    ext.dokka_version = '0.9.16-eap-2'
+    ext.dokka_version = '0.9.17'
     ext.eddsa_version = '0.2.0'
     ext.dependency_checker_version = '3.1.0'
     ext.commons_collections_version = '4.1'
@@ -431,6 +431,6 @@ if(file('corda-docs-only-build').exists() || (System.getenv('CORDA_DOCS_ONLY_BUI
 }
 
 wrapper {
-    gradleVersion = "4.4.1"
+    gradleVersion = "4.8"
     distributionType = Wrapper.DistributionType.ALL
 }

constants.properties

@@ -6,7 +6,7 @@ proguardVersion=6.0.3
 bouncycastleVersion=1.57
 typesafeConfigVersion=1.3.1
 jsr305Version=3.0.2
-artifactoryPluginVersion=4.4.18
+artifactoryPluginVersion=4.7.3
 snakeYamlVersion=1.19
 caffeineVersion=2.6.2
 metricsVersion=3.2.5

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.8-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.4.1-all.zip