Update to Kotlin 1.3.70

Fixes gh-8064

gradle.properties

@@ -3,4 +3,4 @@ gaeVersion=1.9.78
 springBootVersion=2.2.5.RELEASE
 version=5.3.0.BUILD-SNAPSHOT
 org.gradle.jvmargs=-Xmx3g -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError
-kotlinVersion=1.3.61
+kotlinVersion=1.3.70

gradle/dependency-management.gradle

@@ -10,7 +10,7 @@ if (!project.hasProperty("springDataVersion")) {
 	ext.springDataVersion = "Moore-SR+"
 }
 if (!project.hasProperty("kotlinVersion")) {
-	ext.kotlinVersion = "1.3.61"
+	ext.kotlinVersion = "1.3.70"
 }
 if (!project.hasProperty("locksDisabled")) {
 	dependencyLocking {