Dependency Version Updates (#1517)

Release plugin 2.8.0 fails on JDK-12 and Zulu in docker containers.
Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

build.gradle

@@ -21,7 +21,7 @@ plugins {
   id 'io.spring.dependency-management' version '1.0.7.RELEASE'
   id 'me.champeau.gradle.jmh' version '0.4.8' apply false
   id 'net.ltgt.errorprone' version '0.8'
-  id 'net.researchgate.release' version '2.8.0'
+  id 'net.researchgate.release' version '2.7.0'
 }
 
 group = 'tech.pegasys.pantheon'