[FLINK-4261][tools] retry in case of failed snapshot deployment

Unfortunately, we can't deploy snapshots atomically using the Nexus
repository. The staged process which leads to an atomic deployment is
only designed to work for releases. Best we can do is to retry
deploying artifacts in case of failures.

- introduce retry in case of failure of snapshot deployment
- simplify deployment script

This closes #2296

tools/deploy_to_maven.sh

@@ -89,26 +89,25 @@ echo "detected current version as: '$CURRENT_FLINK_VERSION' ; hadoop1: $CURRENT_
 #
 
 if [[ $CURRENT_FLINK_VERSION == *SNAPSHOT* ]] ; then
+    MVN_SNAPSHOT_OPTS="-B -Pdocs-and-source -DskipTests -Drat.skip=true -Drat.ignoreErrors=true \
+        -DretryFailedDeploymentCount=10 --settings deploysettings.xml clean deploy"
+
     # Deploy hadoop v1 to maven
     echo "Generating poms for hadoop1"
     ./tools/generate_specific_pom.sh $CURRENT_FLINK_VERSION $CURRENT_FLINK_VERSION_HADOOP1 pom.hadoop1.xml
-    mvn -B -f pom.hadoop1.xml -DskipTests -Drat.ignoreErrors=true -Pdocs-and-source deploy --settings deploysettings.xml
-
+    mvn -f pom.hadoop1.xml ${MVN_SNAPSHOT_OPTS}
     # deploy to s3
     deploy_to_s3 $CURRENT_FLINK_VERSION "hadoop1"
 
-    # deploy hadoop v2 (yarn)
-    echo "deploy standard version (hadoop2) for scala 2.10"
-
     # hadoop2 scala 2.10
-    mvn -B -DskipTests -Drat.skip=true -Drat.ignoreErrors=true -Pdocs-and-source clean deploy --settings deploysettings.xml
-
+    echo "deploy standard version (hadoop2) for scala 2.10"
+    mvn ${MVN_SNAPSHOT_OPTS}
     deploy_to_s3 $CURRENT_FLINK_VERSION "hadoop2"
 
+    # hadoop2 scala 2.11
     echo "deploy hadoop2 version (standard) for scala 2.11"
     ./tools/change-scala-version.sh 2.11
-    mvn -B -DskipTests -Drat.skip=true -Drat.ignoreErrors=true -Pdocs-and-source clean deploy --settings deploysettings.xml
-
+    mvn ${MVN_SNAPSHOT_OPTS}
     deploy_to_s3 $CURRENT_FLINK_VERSION "hadoop2_2.11"
 
     echo "Changing back to scala 2.10"