Nexus publishing: increase timeout during transition checks. (#289)

- Increase number of attempts from 60 to 180
- Increase delay between attempts from 2 to 3 seconds

This increases the total timeout from 2 to 9 minutes.

build.gradle

@@ -17,7 +17,8 @@ nexusStaging {
     packageGroup = GROUP
     username = System.getenv('NEXUS_USERNAME')
     password = System.getenv('NEXUS_PASSWORD')
-    numberOfRetries = 60
+    numberOfRetries = 180
+    delayBetweenRetriesInMillis = 3000
 }
 
 allprojects {