Explicitly configure some maven artifactIds (#1853)

Some auto-generated maven names cause collissions when used with the gradle
publish plugin, namely `core` and `util`.  Rename two jars that have such
a colission so the colission doesn't occur.
Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

services/util/build.gradle

@@ -14,7 +14,7 @@
 apply plugin: 'java-library'
 
 jar {
-  baseName 'services-util'
+  baseName 'pantheon-services-util'
   manifest {
     attributes(
       'Specification-Title': baseName,
@@ -25,6 +25,14 @@ jar {
   }
 }
 
+publishing {
+  publications {
+    mavenJava(MavenPublication) {
+      artifactId 'services-util'
+    }
+  }
+}
+
 dependencies {
   api project(':util')
   implementation project(':metrics:core')