Add stacktrace parameter to release build

The release is failing on the fetchContributors task, but is not showing
the actual stacktrace.

Debugging for #1721

[ci maven-central-release]

.travis.yml

@@ -48,7 +48,7 @@ script:
   # We are using && below on purpose
   # ciPerformRelease must run only when the entire build has completed
   # This guarantees that no release steps are executed when the build or tests fail
-  - ./gradlew build idea -s -PcheckJavaCompatibility && ./gradlew ciPerformRelease
+  - ./gradlew build idea -s -PcheckJavaCompatibility && ./gradlew ciPerformRelease --stacktrace
 
 after_success:
   #Generates coverage report: