Added --debug option to get HTTP request logged

for a maven central synchronization issue on Bintray

Author: kuniss

.travis/releaseOnTag.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 set -ev
 if [ -n "${TRAVIS_TAG}" ]; then
-  ./gradlew release "-PreleaseVersion=${TRAVIS_TAG}"
+  ./gradlew release "-PreleaseVersion=${TRAVIS_TAG}" --debug
 fi