Update build scripts for artifactory.

build.gradle

     repositories {
         maven {
             name 'snapshots'
-            url 'http://nexus.dmdirc.com/nexus/content/repositories/snapshots/'
+            url 'http://artifactory.dmdirc.com/artifactory/repo'
         }
     }
 }
     repositories {
         mavenCentral()
         maven {
-            url 'http://nexus.dmdirc.com/nexus/content/repositories/thirdparty/'
+            url 'http://artifactory.dmdirc.com/artifactory/repo'
         }
     }